Will '69 302 heads (supposedly with oversized valves) make more power than 289 heads with 1.78 / 1.45 valves? The '67 289 heads (53/54cc)will give me a higher compression ratio but I'm afraid the smaller valves will suffocate the engine. How much is a valve job to outfit the heads with 2.02 / 1.60 valves? Any ideas?
If you must ask the question you can't afford it? But seriously I had my 76 302 58cc heads done with chevy 1.94 intakes (just not alot of room for 2.02) ported and polished heads, screw in studs for around 400 bucks then almost 6 years later had them fitted properly with bettter ford valves,seats,guides to even out the geometry using same length pushrods and performance springs for another $400 or so. I could have bought Darts or world products for a little more. Have fun
Yep, zwhitr is right.. you can end up with a bunch of money in these old heads if you aren't careful. Either buy bolt-on retrofitted cast heads from a reputtable supplier or simply go with the aluminum heads from Summit or Jegs. I bought ported and retrofitted cast heads with 2" intake and 1.6" exhaust for $600. I believe they were $500 if you didn't want any porting done. d
Yeah what they said, i bet i have upwards of $700 or so in my 65 289 heads. They perform great but for a few hundred more i could buy some that perform as well or better out of the box.
The reason why I ask is because there are some good deals on ebay for heads with oversized valves, new springs and all. Under $200 for a really decent set of heads. Performer RPM heads are over $1000.
you get what you pay for but I also think performer heads are over-rated I believe world products are a better head and darts are more chebby style. ps don't go more than 1.94 unless you gotta great big cam and your running 4 grand all the time with big tube headders they are for top end not for the street you will lose fuel mixture velocity just my .02
The cam lift is .496 / .520 @ valve. Desktop dyno shows very noticeable power gains with larger valves, so I may take the heads off my engine and see if they are in fact what I bought with the car. They are supposed to be '69 heads with over-sized valves, ported and polished.
look for a set of svo/frpp gt-40 y or x heads in aluminum. you can pick them up for 400-700. i got mine brand new for 650. not the best heads out there but are a huge improvement over stock and for the price they are hard to beat. down the road they can be ported, gastket matched etc. plus if you have a problem, they can be repaired easier than cast. they will save you about 22lbs per head in weight. yes i did verify the weight savings by scaling my stock heads and the aluminum heads.
As far as stock heads got, stick to the heert-shaped chamber heads. i.e. the 65-68 289 heads and even some of the 58cc 302 heads. Don't waste your time with the 63 and 69cc heads. The 69cc heads were on all '76-79 302's. Any SBF head after '73 had torque down nuts on the rockers and are NOT for use with hot street cams, as you'll need the adjustment ability. On all the 289 and pre-'73 heads you won't get a valve any bigger than 1.94 on the intakes and you'll find alot of machinists are too leary of installing an exhaust valve any bigger than 1.50 aswell, even though a 1.60 will fit fine. Now on the '74 and newer heads, you can use the 2.02/1.60 combo. How so? Because the smaller spark plug. On the pre-'73's the spark plug is much too big to allow those valves. In all reality, there's no real difference between the performance of the 2.02 and the 1.94 when installe din the same head. The major down side to the 2.02 is you'll end up gaining CC size because the 2.02 will require excessive unshrouding to make it actually perform. Long story short- stick to a 1.94 only in a stock head. I have about $625 into my '66 Hi-po heads and they have 1.94/1.60 ss valves and I had the exhaust and intake hogged as far as they'd go. On the average most shops when doing a valve job will replace the valves and cut new seats. When jumping to a larger size of valve, there's really not any cost difference, since it's now such a common practice. Most of the cost is in the valves themselves. My machinist will hog the SBF ports for an extra $100. Whn done these heads will out flow a GT40, no sweat and run right with the Windsor Jr's while still retaining the 54cc quinch. (i have my flow specs around here some where) If you go aftermarket, go with Edelbrocks, Trick Flows or World Products Windsor Jr or Sr. Also -- I'm assuming I have the same cam in my II as you do in yours.
Great info! That'll help quite a bit, thanks. If you're running an Edelbrock Performer RPM cam we've got the same cam.
Yep sure is. The cam NEEDS or better said, REQUIRES a really good set of heads, headers, and minium 2.25 exhaust. If you have an auto, you'll need at least a 2400 stall to get by. It'll run on a stock stall but will seem doggy off the line. Stock heads will choke this sucker like a Prostock with 2" single exhaust. Bad news. Personally I really liked the Weiand Stealth (or Edelbrock RPM) because the dual plane intake made it more streetable and had a better and broader torque band. I have a dual quad Tunnel Ram on there now and besides the PITA tuning it runs like a bat outta hell but is not a very tame pony in traffic. I think a single plane Victor Jr intake would kinda meet bother worlds right in the middle but I like the intimidating look of the Ram. I'm betting a single carb ram would probably be a tad bit easier to deal with, but looks kinda dorky and kinda pointless with the hi-rise intakes out there these days. It'll be up to you on the head situation. Oh! Also do forget about AFR heads, they have an enticing selection of heads from the 165's to the 205's for the SBF.
Even if you can manage to fit larger valves in a given factory head, there is the issue of shrouding, because the combustion chamber wall is too close to the valve, and it inhibits flow. The 69-74 351W heads have larger ports(at least on the intake side) and larger 1.84" x 1.54" valves. They also have larger chambers, which lets them breath better due to their unshrouding the valves. I had a set ported on the exhaust side, and milled to increase compression, but otherwise stock, and they made nice power on my old 302. As hardcore Blue Oval as I am, I will still say that aside from the BOSS parts, all the factory 289/302/351W heads just plain suck for serious performance. Running those heads is like sucking a gallon of soda through a coffee stirrer.
As a machinist in a head shop, and as a DIE HARD Ford man, i can tell you a few things-- most of which have already been addressed (but i can second most of those notions) first off, as for early heads are concerned... the gains you will get out of PURE stock early 351W heads will surpass whatever raised compression gains you will achieve by using PURE stock 260/289/early 302 heads. that being said, with some mild port work to the exhaust side, and a little bowl blending the early 351w heads can keep up with a gt-40 or gt-40 "p" cast iron head-- both of which have the 1.84 intakes. (one must take serious note that the 351's had the larger intake ports, and larger stock Intake valve size) i will say however that in stock form the gt-40's are the best heads to find, 1998-up 302 equiped explorers have these. (i saw a bare set of these on ebay yesterday for a buy now price of 160.00) also a good point was made about oversize valves, i personally try and discourage people from the typical 2.02/1.60 and steer them towards the more streetable and sensible 1.94/1.60 (requires less unshrouding of the valves in the chamber, if any at all) any of these heads will benefit from mild exhaust side work (you can take that egr bump outta there, dont worry about diggin too deep-- there is plenty of meat there) also anyone wanting to go cam lift around .500 or bigger should definatly invest in screw-in studs/guideplates and springs to suit your cam profile. heres my daily driver specs for those who care.... '68 302 block .030 zero decked with .440 dome trw forged pistons, stock 302 rods with waveloc ARP 5/16 bolts (going to 3/8 takes too much away from the meat on the rods themselves), stock 302 crank, .010/.010 (rotating assembly balanced), .500 lift 300 advertised duration cam double row timing chain and a performance oil pump (something that supports bottom of gears in the pump will keep you form getting walk/wear on the bottom pump plate... spend the extra 20 bucks... its worth it) '69 351w heads, 1.84/1.50 valves, bronze guides, screw-in studs/guideplates, crane double springs with titanium retainers with a seat pressure of 120 lbs., crane energizer roller rockers, edelbrock performer RPM intake with a knocked down center web (also port matched), holley 600 w/ vac. secondaries for some sense of streetability. msd 6al ignition box (dont recommend because motor "pops off" when it hits the rev limiter, which is 7000) hedmen full length headers with dual 2 1/2 pipes going into flomaster 40 series mufflers. desktop dyno puts it at about 400 HP without adding in the hotter ignition or roller rockers. its in my 77 t-top mustang II with a 2800 stall/stage II shift kit C4 tranny, and a 3.43 rear hooked up to 205/65/15 rubbers in the back. makes for a fun ride to work everyday.... and gets about 8 mpg on a good day. i have typed too much.... need...... beer....... now.......
That motor setup is very similar to the previous 302 I was running in my car. A couple points: 5.155" 289 rods would give you some small flow improvement (more overall power, as well as greater durability) over the 5.09" 302 rods, because of the improved rod/stroke ratio. Also, those 289 rods generally have ribbed caps, which add some degree of strength. Don't believe the desktop dynos, I bought one a few years ago, and it told me my 332 stroker is making 650+ hp. (I know it's high by at least 100 hp) I began writing my own virtual dyno program last year, and assuming I get enough time to finish it, it should be relatively accurate, at least compared to most of what's on the market now. I would think a 302 setup like yours would make somewhere around 340hp at the flywheel / 270hp at the tires, if tuned properly. I agree with your opinion on the rod bolts. I think 3/8" bolts in a stock rod is crazy. ARP bolts have ungodly strength compared to factory parts(and Ford forges some damn good fastenings, too). If your street/mild strip 302 breaks a stock reconditioned rod with ARP bolts, you better start avoiding walking through open areas, because lightning is most certainly going to strike you next. I've punished 302 "grenade" stock-lower-end motors unbelievably hard in the past, and I've yet to break anything in the short block. The 302, even in pure stock form, is a SERIOUSLY durable little beast. And hey, if your rev limiter is pissing you off, just pull the pill on it, and it'll remove the rev limiting function, or better yet, install a new pill with a higher RPM setting.
