96 Gt.. To Swap or Not To Swap...

[darkmajesty06]

Hello all,

This is my first major post.. so sorry for the massive question here...
I have a 97 Mark VIII just sitting out in my yard.. It used to be my daily driver.. but when i found out headlights were like 300 bucks a piece and to replace the air bag system on the car would cost more than what i paid for it.. i just sit it in the yard. Its been almost 3 years since Ive touched it.. but now I'm reading about all these people putting the mark VIII engines into their sn95s and I have a stout one just sitting outside.. So I'm curious.. I've tried to find write ups about it but not much luck. Anyone know all the specifics to the swap.. I guess i cant keep the stock manifold and i guess the IRMCS cant be used either?

I also have another option.. I am buying a Complete PI kit from a 01 Saleen, other than the sweet, sweet sound of a 4V, are there any other benefits from the mark VIII swap, that the pi kit couldn't bring to the table?! I know that 4.6 4v was stout in that heavy ole mark.. I can only imagine what it would allow me to do in my gt. I want it to be worth it though, and i have a free motor.. Not getting a bad deal on the pi swap either.. so I'm just looking for some suggestions right now. It'll be a few months before i do the swap.. I figured, while the motors out, might as well rebuild it, put full exhaust and some pulleys on the motor. So thanks for any suggestions and I hope i can find the help i need, if this motor swap does happen.

 

[N8Dogg98]

Hello all,

This is my first major post.. so sorry for the massive question here...
I have a 97 Mark VIII just sitting out in my yard.. It used to be my daily driver.. but when i found out headlights were like 300 bucks a piece and to replace the air bag system on the car would cost more than what i paid for it.. i just sit it in the yard. Its been almost 3 years since Ive touched it.. but now I'm reading about all these people putting the mark VIII engines into their sn95s and I have a stout one just sitting outside.. So I'm curious.. I've tried to find write ups about it but not much luck. Anyone know all the specifics to the swap.. I guess i cant keep the stock manifold and i guess the IRMCS cant be used either?

I also have another option.. I am buying a Complete PI kit from a 01 Saleen, other than the sweet, sweet sound of a 4V, are there any other benefits from the mark VIII swap, that the pi kit couldn't bring to the table?! I know that 4.6 4v was stout in that heavy ole mark.. I can only imagine what it would allow me to do in my gt. I want it to be worth it though, and i have a free motor.. Not getting a bad deal on the pi swap either.. so I'm just looking for some suggestions right now. It'll be a few months before i do the swap.. I figured, while the motors out, might as well rebuild it, put full exhaust and some pulleys on the motor. So thanks for any suggestions and I hope i can find the help i need, if this motor swap does happen.

Nick McKinney at MHS has a great article on his website about this very thing: ModularHeadShop Recession Buster 2V combo

The Mark VIII engine has the desireable aluminum teksid block (saves about 70 lbs over the iron block) and flat pistons. Therefore if you install PI heads on this block you'll have roughly 11:1 compression. If you follow Nick's advice and notch the pistons, you can run a cam w/ an aggressive intake centerline which will improve the mid-range torque. The article I linked is a GREAT write up. I plan on doing something similar in the future.

As far as the 4V sound, I definitely think my cammed 2V sounds as good as if not better than a 4V w/ exhaust.

 

[Maxpowers]

Take the free 4v out and don't look back. How many miles are on it?

No reason to rebuild it unless so.thing is wrong. Do a compression test to find out.

 

[1987stangman]

Take the free 4v out and don't look back. How many miles are on it?

No reason to rebuild it unless so.thing is wrong. Do a compression test to find out.

I second that. You will be much happier with the 4V than a P.I swap.

 

[N8Dogg98]

I disagree. The Mark VIII intake manifold runs out of breath at 5K rpm's and really won't make all that much power unless it's supercharged or you find a cobra intake manifold. Now there's nothing wrong with a B-headed 4v car, except that they don't make much low end torque. A 4V short block w/ PI heads and nice cams will make around 11:1 compression, have a very broad torque curve, and would be more fun to drive on the street compared to a 96-98 Cobra and would beat it in the 1/4 mile.

 

[darkmajesty06]

The 4v has around 244,000 miles on it. It ran strong when i drove it.. i only put around 9k for the year i had it.. but they were rough miles.. lol. Alright, I will follow this guide and see how it goes. I have heard over on Lincoln vs Cadillac forums.. that guys have around 400,000 on there motors and still romping on em everyday.. but to be on the safe side.. i think i need to rebuild it with as many miles as it has on it. So im assuming no one thinks i should just keep my 123k gt motor and do the pi swap on it? I know its a 4v semi cobra motor.. but if I'm not mistaken.. the 96 mark motor was like 260 hp.. if i do the pi swap on my motor, wouldn't that put me in the 280 with a full pi.. then headers, exhaust, pulleys and a tune put me around 300hp? Just trying to get the best hp for the buck here. Thanks for the link too!

Edit: I was reading the guide and a fellow made 273 with full exhaust on the mark VIII motor.. I really love the sound of the 4v.. but it sounds like my year model motor.. isn't as great as the 97-98.. figures.. I get a 96 gt when i should have bought a 02 gt.. i bought a 96 mark viii when i should have gotten the 98... LOL. Story of my life.. either way.. I am sure someone can chime in if the numbers i have stated for a npi motor to pi motor are wrong.. but if not.. doesn't seem like its worth it.. especially with my motor is pretty decent shape.

 

[N8Dogg98]

I think you're misunderstanding. The idea here is to install the PI heads and intake on to the Mark VIII short block, then install that engine into your Mustang.

 

[darkmajesty06]

Ahh, well yeah.. that could work too.. lol. I am a slow learner.. gotta wait for me. Any who.. if i did the pi swap to this motor.. I wouldnt have to mess with the irmcs.. right? Those are in the heads of the mark viii motor. and if i did the intake swap out on it.. then i could reuse all my top end stuff.. but i am curious about manifolds.. I would have to use the marks because of it being 4v, so i would then just order a set of long tubes for a 96-98 cobra or a 99-01 cobra? Lastly this might sound completely stupid.. but when they refer to a 4v.. instead of two.. the valves are in the head.. right?! So if i swapped to a 2v pi kit.. I wouldnt be 4v anymore? Once again.. sorry for my ignorance to that part... shame on me.

 

[N8Dogg98]

Ahh, well yeah.. that could work too.. lol. I am a slow learner.. gotta wait for me. Any who.. if i did the pi swap to this motor.. I wouldnt have to mess with the irmcs.. right? Those are in the heads of the mark viii motor. and if i did the intake swap out on it.. then i could reuse all my top end stuff.. but i am curious about manifolds.. I would have to use the marks because of it being 4v, so i would then just order a set of long tubes for a 96-98 cobra or a 99-01 cobra? Lastly this might sound completely stupid.. but when they refer to a 4v.. instead of two.. the valves are in the head.. right?! So if i swapped to a 2v pi kit.. I wouldnt be 4v anymore? Once again.. sorry for my ignorance to that part... shame on me.

If you were to go the PI route, you wouldn't be able to use the 4V cylinder heads (and yes that means 4 valves/cylinder). Therefore, the IMRC's wouldn't be used either as they are part of the 4V heads. When we say PI swap, generally that means taking the 2V cylinder heads, cam covers, and intake manifold from a 99+ Mustang and installing it on a NPI, 96-98 Cobra, or 93-98 Mark VIII short block.

No offense, but it doesn't sound like you know very much about engines, specifically the modular ford engines. IMO this is not something you should do until you fully understand these engines and are confident you could swap engines. I'd hate to see you start tearing into this project only to realize that you're in way over your head.

 

[darkmajesty06]

Yeah, im knowledgable but im from a chevy family and older chevys at that... where if I have a 305, I can just swap in a 350 or a 454, wire up my choke and go on down the road the next day. I was never for sure why there were 4 valves, I guess two intake and two exhaust valves... im just used to one set per cylinder.

No offense taken, but next time don't assume no mechanical ability is present. I will admit that im silly when it comes to modular motor. So I thought maybe ford had set the valves somewhere else. Why? I guess because they could. So sorry for sounding dumb in my last post.

 

[N8Dogg98]

Yeah, im knowledgable but im from a chevy family and older chevys at that... where if I have a 305, I can just swap in a 350 or a 454, wire up my choke and go on down the road the next day. I was never for sure why there were 4 valves, I guess two intake and two exhaust valves... im just used to one set per cylinder.

No offense taken, but next time don't assume no mechanical ability is present. I will admit that im silly when it comes to modular motor. So I thought maybe ford had set the valves somewhere else. Why? I guess because they could. So sorry for sounding dumb in my last post.

I didn't assume you don't have mechanical ability, I'm just looking out for ya that's all. It's great that you're doing some research and reaching out to others to gain some knowledge about these Ford products. Keep doing your research and you'll find that the swap really isn't all that difficult. Friendly advice: it's probably easier to drop the engine by unbolting the K member and raising the car (similar to doing a camaro engine swap). I'd love nothing more than for you to do an engine swap and have a nasty 300 RWHP stang. Good luck man and let me know if you have any more questions.

 

[darkmajesty06]

Aah, Thanks. I meant no offense to you either, I was trying to merely let ya know, that i knew a little. Hey, I appreciate all the help from you as well. I would love a 300 Horse mustang too.. I just want something that a minivan or a freaking dodge neon cant touch.. and my car stock.. most likely would get stomped by both.. so I have not even tried to take it to the track or to the twisties yet.... sigh...

Let me ask ya'll.. what are the real world gains of a complete pi kit swap? What if I added a nice set of long tubes, pro chambers and SLPs? Where exactly would that put my stock 2v at? Mini van and dodge neon killer? As long as I can clean the track of rice all day.. Im good to go. I know i am no vette, ta, wrx or ls series killer.. but really I would like to hold my own.. as there is a lot of rice in my area. What would the gains of those same said parts be on the mark 8 block?

 

[N8Dogg98]

The PI swap w/ LT headers, o/r mid pipe, cat back, CAI, and aftermarket plenum/tb should net above 260 RWHP. If it were me I'd also buy a pair of cams to toss in there, and replace the timing chains, guides, tensioners, and cam & crank gears. May as well do it right the first time. If you were to add cams to this you'd probably be around 280-290 RWHP.

Forgot to ask, how many miles are on the Mustang's engine? Keep in mind these engines run well into the 400,000 range, so your short block is probably fine (assuming you never ran it w/o enough oil, its had regular oil changes, etc...)

 

[darkmajesty06]

I am at 123,xxx on the mustang.. im an otr trucker, so I only drive it one every few months. Now those numbers were for a 2v mustang short block? How difficult would the mark viii short block swap be, with me doing the pi kit on it? That would eliminate alot of guess work for me, right? Only bad thing is, the mark viii block is at 225 or 235,xxx miles..
So since you confirmed that our 2vs are good till 400 if I do my up keep.

 

[N8Dogg98]

Yep, as long as it doesn't burn oil you're probably fine. If you were to do the 4V engine block I'd take Nicks advice and take it apart, have the pistons notched for valve reliefs, and replace the bearings and piston rings.

 

[darkmajesty06]

I will keep it in mind.. I think for now im going to try the pi swap on my mustang motor. It just gives me a reason to add some nasty cams and hopefully stay in front of the mini vans... lol, its sad when a gt has to worry about mini vans at the track.

 

[2slowgt]

4v swap!!

back from the dead! did you do the pi swap?
dont do the pi swap, i did it, now im doing the mark viii swap!!!!, the base mark viii will put you where you want to be hp wise. you can use your mark viii engine, get a 97-98 mark viii intake manifold and delete the imrc's and get some longtubes with offroad midpipe. no ecm needed and only a few wires to lengthen.
go HERE: it is an awesome write up!!
Step by Step guide to installing a Mark VIII motor in a 96+ GT. - MustangForums.com