351W/408 stroker swap into an 87 GT. Everyone welcome, teach me!

astronut1885

Founding Member
Jan 31, 2002
1,899
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39
Assonet, MA
Hey guys. Over the last two months, I've been making plans for the future of my car. Last spring I built my motor up with a friend. We didn't do the bottom end, but we did GT40P heads, E cam, GT40 intake, roller rockers, smog delete, etc. The motor makes some power, 258 RWHP when dynoed untuned, but it isn't enough for me, and it was just a starter motor. I've recently come up with the idea of doing a blown 331, much like sirsureshot, but I am not a fan of blowers at all. I prefer N/A, it's just something that appeals to me. I've heard that 347 strokers are not good for daily drivers, so that's out. Now I'm thinking about a 351W block swap. I know I could get one cheap, and I'd take time building it up. I'd probably bore and stroke to 393, 408, or 418, and I'd put a good H/C/I on it. I'd want to stay EFI, and I know it's doable. I'd shoot for AFR205 heads, a big cam (not sure what kind, maybe a Curtis custom), and a big intake like an Edelbrock Performer RPM or something. I'd also do all the bolt ons. Here's what I know- most of my bolt ons, like my CAI, roller rockers, MSD ignition, and catback are swappable. I know I'd need special LT headers, and a new midpipe (i'd get another ProChamber, I love my current one). I also know I'd need different motor mounts, and some other stuff. Here are my concerns-
-I'd need a roller cam block. I know they exist, but where could I look?
-I know the 351 block is heavier, will it mess with my handling and weight distribution, or will my progressive rate springs compensate?
-Will a T-5 (or in my case, a TKO500 with appropriate bell housing for 302) bolt up?
-What is the best CID to stroke to for a daily driver/ street car?
-Where can I get a quality stroker kit?
- What other issues arise when swapping a 351W in?
If anyone who has experience with this please throw any info or ideas out, or send me in the right direction. I want to know every single bit I can about this whole idea, so i can make a good decision. Thanks a ton guys!
 
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I did some reading, it seems I can get shorty headers for the swap, so a new midpipe isn't needed. That's good news. Also, the weight issue could be minimal, because I'd be adding aluminum heads, vs. the heavy cast irons on my 302. I could also kick the battery to the trunk, and my a/c and smog stuff is already gone, so I don't think I'd be far from a stock GT's weight distribution. I don't know if a 393 stroker would be better than a 408 for longevity though, because I know the 347 is not as sturdy as the 331. Give me some info guys!
 
well..your in for a lot of money to be spent...even if you think "ill reuse this" or "ill reuse that" you still end up buying new stuff and it ends up costing alot more...if you like to drive around town and cruise around alot..be careful what you pick for a motor..cause thats what i USE to do but now find myself cruising where there arnt alot of people or traffic

me personaly..i wish i would of built a nice 331...and then put a blower on it...the 331 would make enough power for me around town..and if things got serious i would know i had a blower to help me out in the upper RPM's

as for your questions,

you can use a 351 non roller block(i did) i then use the crane retro fit lifters...they are spendy..but worth it, but if your stuck on one..i beleave its the 94+ 351's that are roller

as for handleing..cant really say..my car was factory before and now has narrower tires up front..so i dont know for sure

the stock T5 and bell will bolt up..i used my stock bell and tranny at first till i got all the parts needed for my TKO swap..but keep in mind you can go this route..just plan on upgrading to a TKO cause the T5 wont handle it for long..also..the TKO uses a different clutch disc so dont plan on installing the clutch that you want to run with your T5..to get me by till i had the money/parts i used my stock bell and tranny and just bought a cheap Ram clutch from summit to get me by(Part# RAM-88794)

as for CID..id say 393..but you should contact Brian at ADperformance for your stoker kit and he can help you out with that..he is a super nice guy to deal with..can answer alot of your questions concerning strokers,anyone that has delt with him will tell you he is the guy to go to for a kit(www.adperformance.com)

humm other issues? well you can use your same mid pipe..but why..with a motor that size you should upgrade to LT's and 3 inch exhaust anyway...as for a intake for EFI..im using a edelbrock victor 5.8..but wish i would of went with a TFS 351 intake with the 90mm opening..TFS also came out with there new box style EFI intake that id like to use but it will not clear my hood(2.5)

also plan on a complete upgrade to your cooling system and fuel system..im using my stock style fan and clutch(HD clutch,new fan) and a griffen rad.,high flow steward pump with high flow 180 thermo, as for the fuel system im using a 255 intank pump kirban FPR and stock lines and rails for now..but ill be upgrading to X2C's complete fuel system...

there is still alot to cover..i could go on and on about this and that for the swap and what to use/look out for..but i think i said enough for now...any questions just ask...
 
I have a 255 LPH fuel pump, and a Crane AFPR. I'd get a nice big MAF and TB to go with it. I looked at the TFS intake, I like it alot better than the Edelbrock, so I'd probably get that too. I think 2 1/2 exhaust would get me by for the time being, but eventually I'd upgrade. It's an easy way to save money, keep my current setup which I really love, and allow me to put my catted H back on (not that I think I'd pass the sniffer). For cooling I have a brand new 2 core rad, a stock tstat, and I will be soon upgrading from the clutch fan to a MKVIII electric fan. My car runs no warmer that 192* right now, and that's in traffic, on the highway, WOT, anywhere. I'll be getting a TKO500 setup in a month and a half, so it'll already be on my 302. I don't plan on installing a motor for over a year, I want to build it right. There isn't much I'd reuse. I want a new stroker bottom end, 7qt Milodon oil pan, stud girdle, AFR 205s, I'd get a custom camshaft ground, TFS 351W intake, roller rockers, new roller lifters, hardened pushrods, MSD distributor, etc. I want this motor to essentially be a 0 mile fresh motor.
 
Demon, I just looked at your pics. I see that you used stock brackets for your accessory drive. I have the FRPP A/C delete like you have, and I have the smog deleted with a 3G alt sitting in the alt bracket. Can those just bolt up to the 351W block? I've read that you need special brackets, but from what I see, you didn't.
 
Well, I think I found the kit to do the roller cam conversion on the flat tappet 351W. It's like 60.00 from FRPP and includes the spider hold down, bolts, and the dogbone things that go around the lifter bosses. Apparently I'd have to get the block drilled and tapped to mount the spider, but then with the addition of some roller lifters, I'd be able to run a roller cam. I want to get an EFI block so that it has fuel rails, because non-EFI blocks would mean I'd have to modify some stock 5.0 rails, and I'd rather not do that. I imagine some companies sell better flowing 351W rails, which would be a good idea. I also found the crank spacer needed to run the serp. belt system on the 351 with my alternator and P/S pump. I'd get a new high volume water pump for a 302, because it's the same fitment, and I'd probably swap my underdrive pullies over to the 351 if it can be done. I can't find any info on any hardened pushrods for a 351W. I got some FRPP ones for when I built my 302, and I'd like the same for the 351. My roller rockers would be swapped onto the heads I install on the 351, probably AFR 205s or 185s, maybe TFS TW heads, either way the heads will get ported out, same with the intake.
 
if your planing on upgrading to LT's later...id just do it as your puting the new motor in..trust me..its alot easyer that way

the stock alt bracket works...and as long as you use a Romac balancer the crank pulley is fine no spacer...and if you already have the FRPP a/c delete then all you need is the swap brackets from summit (FMS-M8511B351) it has two brackets..one for PS and one for a/c..but i dont have a/c so if you look at the pic of my motor on the engine stand you can see the black PS swap bracket..a/c bracket i didnt use

you can convert a non roller block to roller with that kit but its not as strong or reliable as the link bar lifters..iv heard of ppl having the dog bone "arms" bend and let the lifter pop out ect., you also have to drill into the block

modding the fuel rails is easy..there is fuel hose connecting the two together in the back and front....cut it off and go to the store and by some fuel hose and small clamps..cut the old fuel hose off and test fit it on the motor and mesure to see about how much you need and slap the new fuel line on and clamp each end, if you dont wanna do that...you can by aftermarket fuel rails for a 302..they will fit a 351..but either way you will have to connect the two rails together in back...iv also heard of ppl using SN95 rails..they flow better

you might want a high flowing thermostate from Stewart...i didnt use one and i kept blowing my water pump gasket out..high flow pump + cheapy thermo = to much presure

keep in mind 90% of stuff swaps from the 302 to 351...no matter what..once you have your heads installed you will have to CHECK for correct push rod length...crane sells adjustable pushrods for checking....make sure you use a solid lifter when checking

to learn how to mod SN95 rails for your car..go hear for all the info,all you need is a $10 pipe bender from wal mart
http://www.duggerracing.com/techtips/rails/index.shtml
 
The black P/S bracket you have looks just like my A/C delete, I bet it's the same damn thing. I'd like to get better fuel rails, maybe the SN95s or some aeromotives or something. I'd get a good thermo, like a Mr Gasket or something like that. I don't want LTs at all, if I can avoid them I'll never get them. The lifter conversion thing is the same as what comes in a 302 stock, so I'm not too worried about it, it's cheaper than the link lifters and it's just fine in my 302. I don't know about the balancer. If the motor comes with a 28 oz in good shape, I'll just space the crank and be done with it. If not, I'll get a good one like Romac. I know I'd need a new flywheel, so I'd just get another FRPP one like the one I have now on the 302. On the pushrod thing- I guess I've got something to learn there. I'd probably be using either TFS TW heads ported out, or more likely AFR 205s ported out with roller rockers on top. I guess when it comes time for pushrods I'll have to do what you're saying, then order the custom length I need. I'd want the good hardened ones, and for the rockers I'd either swap my aluminum 1.7s over or get some steel 1.7 rollers, just for added strength.
 
not to mention the SN95 rails hook up to your current fuel lines ..and look stock

if your going to build a nice motor you will want a nice balancer like a Romac..if you get a custom cam from Ed curtis he also sells the Romacs so just get both from him and be done, having a good balancer is worth the investment

as for heads..i wouldnt use the TFS TW heads...if you want better heads like AFR's but dont really wanna shell out the $$$ for the 205's..the 185's should perform very well on a 393..i actually looked at the 185s for my motor...but desided on something different, i beleave there is a admin over at the corral that has a 393 with the 185s with very good results(afr 185s and TFS intake,Ed cam)

oh yea...and i bought a FMS a/c delete kit AND the PS bracket for the 351 swap...and compared the two black brackets, they are different..they look the same but the 351 bracket is larger/longer..hell i cant remember exactly but its not the same..just pay the 50 bucks for the swap brackets use the one you need or both...and what ever you dont use sell on ebay

as for the dog bone conversion..i beleave you must run a small base circle cam with that set up...witch is a PITA...if you use the link bar lifters you can use any 5.0 cam available...which is ALOT, link bar lifters you slide cam in drop lifters in your done, dog bone you have to drill and tap block put that crap in then pay for a small base circle cam...your call i guess you can always discuse that with Ed...he will help you out
 
So any link bar lifters will work? I think I saw those listed on Summit right under the spider thing. I wasn't sure if 205s would be too big for my car, especially since they'll be getting ported/polished, so I bet a well worked set of 185s with the higher compression would work better. How much do those Romac balancers go for from someone like Curtis? Also, am I better off using an off the shelf cam or getting a custom grind?

- Did some reading. I found FTI's website, I think that's who Ed Curtis works for, but I'm not sure. I think for the $325.00, a cam made to match my engine is a good investment over a shelf cam. My E cam worked fine for my current combo, but now I'm shooting for the big leagues. I guess a good balancer would be worth it too, no sense in cheaping out there and risking harmful vibrations.
 
Ok. I've been creating a wishlist on Summit Racing to keep track of what I'll need. I have saved the TFS 351W intake with the 90mm TB opening, the chromed BBK 351W swap headers, the 28oz imbalance billet steel FRPP flywheel, the FRPP crank spacer (if I don't get a Romac damper), the brackets from FRPP for the acc drive, and a pair of poly motor mounts. I also found the link lifters from FRPP, an ARP oil pump driveshaft for the 351W, and the FRPP oil pan kit. I think I'll use that only because a 7qt Milodon will sit lower, and my car already bottoms out like a bitch. Last night I tore the midpipe off the header at the mall on a speed bump. Now I gotta go put a new bolt and nut in the flange (it stripped the stud out). I also found the MSD TFI dizzy for a 351W, but for some reason I remember reading that you have to change the drive gear because I'll be running a roller cam instead of a flat tappet. I want to run a mains girdle, but I also want a windage tray, and I don't know if those can work together. Also, with the FRPP oil pan kit with the pickup and dipstick, will that clear a girdle? On a side note, for some reason I was under the impression that a 351W was a 4 bolt mains block. Now I'm thinking it's a 2 bolt. Which is it? Thanks for all the help so far guys!
 
With the 302 style spider roller lifter conversion, the bores in a 351w block are shorter. Roller 302 blocks have taller bores to accomadate for the dog bone stlye set up. Using this set up on a 351w is not a good way to go. Sometimes the dog bones fail, which is what DemonGT was saying. The retrofit stlye is initially expensive, but worth it in the long run. Retrofit lifters have a lot of positives. More cam selection and more reliability. I think I remember reading a post where someone said that Mr. Curtis talked him out of a small base circle cam, but contact him for sure. Do a search for no matter what parts you are looking for, not that everyones opinions are always right, but you can at least make your own decision after hearing some others horror stories.
 
I run a the crane drop in lifters ($410). I also have the probe girdle wich is a nice fit. Canton pan and pickup fits best with a girdle. I also use a edelbrock 302 water pump with 3 core stock replacement radiator and stock clutch fan, works perfect. I would go with 3 inch exhaust to start if you can. 1 3/4 headers will be "ok". Have you considered the TFS "R" heads? I paid $1486 through summit and made my #'s in sig with all out of box stuff on pump gas (carbed though). I am using an ATI balancer, pricey but a nice piece, needed to make a spacer for it (using 302 pullies).
mike.

http://www.strokerpower.com/photopo...49&password=&sort=1&size=medium&cat=500&page=
 
I'd like to use the FRPP pan if I can, only because ground clearance is a major issue. A friend managed to weld my prochamber back together thank god, so that's dealt with. I have a spankin new 2core radiator, so that would be swapped over. I also stored a FRPP high flow water pump on the wishlist, and a MKVIII electric fan will be in the bay long before the motor is built. Alot of people are saying 3" exhaust, then again alot are saying it's overkill for a 393 (that's what I've decided on for CID). I'll use what I have, and see where it goes. The FRPP lifters are like 400 too, and I like FRPP products, so I'll go with them. I've not considered the TFS heads, because everyone says AFRs are better. I honestly don't know which way to go, although the TFS heads are cheaper.