I want the truth!

[Cobain03]

lol anyways...

aluminum heads. i've heard people say big gains from stock vs aftermarket such as edelbrock or Trick Flow. say i went with edelbrock performer RPM heads or the twisted wedge heads. roughly the same specs. what should i see? my mods are in the sig. keep in mind i have 148 hp and about 197 tq at the wheels. the power is really getting me down and my mind is saying save for a 99+ gt and quit putting money in the 65.

 

[mustangdave]

I think with the heads AND a better intake, you would see 50 or more h.p. and similar tq. gains. The heads won't go it alone; an engine is an air pump and works as a system. Go with the RPM air gap or similar intake.

 

[D.Hearne]

First off, go with 58 cc heads then mill them .030 or so to keep your compression the same. And I agree with mustangdave , loose the Performer intake. Go with a high rise aluminum, I like Ford's A321 , but a Performer RPM will get the same results. Also I recommend 1.7 rockers for whatever heads you decide on, the cam needs a little more help, but not to the point where you need to change it too. The difference from ported stock heads ( E7TE's) to the Canfield's I have ( 1.94/1.60 valves, and the equivalent of AFR165's) was night and day. But remember, the swap is going to move the powerband up the rpm scale, to minimize this, stick with a dual plane intake and the cam you have now.

 

[mustang6788]

The heads and an intake as above will make alot of difference in seat of pants. I am biased towards the trickflow heads, I have the CNC ported 185cc TW heads and you will love them. With an intake and those heads you will pick up atleast 50hp, a mild cam would put you over in my opinion. That is about 0.5sec in 1/4 mile.

 

[ForceFed70]

I'd guess 40HP with a decent intake.

You'll also have to consider a carb upgrade.

 

[ddonaca351]

(imho) 25hp with just the heads and 1.7 rockers. That may not sound like much, but you have to keep in mind, you only have 289 inches to work with... if it was a 302 or a 351 youd probably see another 5 to 25hp respectively.

A performer rpm (not the air gap) intake will not hurt you much down low, but would probably add another 10hp and 5-700 useable rpm up top.

A 600 should be ok for a 289.

DD

 

[Dark Knight]

Look at my sig. Same intake, carb.. it's a roller block with the stock cam which is about the same size as yours but with 1.7 rockers it has a little more lift. And AFR 165's Put 263/290 at the wheels. You should run the car at the track, the MPH is a better indication of HP than the dyno.. dyno numbers can be tweaked or even changed by as little as tire pressure changes.

Oh yeah, my HP was peaking at 6000rpm... but I did port match the intake to the heads..

 

[Vinyl66]

Keep that car! Classics You will kick yourself everyday if you get rid of it for a 99+ Mustang.

You will see tons more power with any good aluminum aftermarket head. Try to get a 58cc if possible so you won't lose much compression. That and a RPM or RPM airgap will REALLY get your car going. What gears do you have now? You will want a 3.55 or better for really good acceleration and to get the engine in it's sweet spot faster.

I had dished!! pistons in my old 302 and all the popular bolt-ons like exhaust, 3.55 gears, RPM intake, and 600 carb. Still had stock heads and cam. I ran low to mid 15's with that combo at 89mph.

Next time to the strip I added some used Twisted Wedge heads (61cc), 1.6 roller rockers, and Comp. XE268H cam and immediately went 13.9 at 100.5 mph. Needless to say I was pleased with the hp increase. It wouldn't take too much to put you ahead of those '99 Stangs.

 

[68keyblr]

You can't handle the truth!!

 

[jikelly]

The aluminium heads also save weight on your front end.

 

[jerry S]

AFR has several articles scanned on their website in which Muscle Mustang and Fast Fords tested a bunch of heads (including stock) on a 331 stroker.

http://airflowresearch.com/articles/ultimate/Group2/Part4/A-P1.htm

Trick flows made peak 438 HP while the RPM Performers made 430 peak HP. Stock heads made 351 peak HP. AFR 185s gave the best peak HP at 448. This test was performed on the same block each time with the cam, carb, and intake remaining constant. ONly the heads were changed. As you can see, the after market heads do make a huge difference.

You would see even better HP numbers with the CNC ported Trick Flows. As cast, the TFs flow 251 cfm intake at .500 of valve lift. CNC ported, they flow 285 cfm intake at .500 valve lift. However, they are appreciably more expensive.

I am sending my heads (RPM Performer) and intake to Avenger Cylinder Heads (part of FPS) for 5 angle CNC porting. At .500 of valve lift, the intake flow goes from 244 cfm to 271 cfm. The guy I talked to said that on their dyno, their test mule engine with the ported RPM Performers made 50 hp more than the as cast RPM Performers. That would put me to 475 hp at the fly. I am looking forward to it.

 

[68stang351]

My buddy has a 302 with an RPM intake, 600 carb, used to have E7's and a stock H.O. roller cam (it is a late model H.O.), and he put a .512 cam and Trickflow Twisted Wedge heads and 1.6 RR's and this motor just came unglued! It's like day and night, even with a 600 carb. The motor just pulls so hard up until 6500, and it still feels good, but that's the most it ever sees because stock bottom end. But I'm definitely a believer.

 

[coolblue65]

I gained about 45 RWHP with the addition of my Trick Flow heads and roller rockers....and that is after losing a lot of compression going from the stock 65 heads to the 61cc Trick Flows.

The car screams...(when it works)

 

[68keyblr]

I gained about 45 RWHP with the addition of my Trick Flow heads and roller rockers....and that is after losing a lot of compression going from the stock 65 heads to the 61cc Trick Flows.

The car screams...(when it works)

This might be a dumb question but....Is there any realistic way to bump the compression back up without changing pistons and/or rods?

I'm thinking of the same swap but don't want to rebuild the bottom end if not necessary and want to keep 10:1 compression.

 

[D.Hearne]

This might be a dumb question but....Is there any realistic way to bump the compression back up without changing pistons and/or rods?

I'm thinking of the same swap but don't want to rebuild the bottom end if not necessary and want to keep 10:1 compression.

What engine do you have with a 10 to 1 ratio ? If you want to keep that ratio, you need to keep the combustion chamber the same size. You can also alter it with head gasket thickness, but not by much. Or mill the heads you choose to get the chambers the size you want them.

 

[68keyblr]

Stock bottom end, with milled stock heads.

I'll probably not want to mill a new set of heads so I guess I'll have to change out pistons. On second thought, I think I'll just wait and build up that 5.8 that I want.

 

[10secgoal]

You can't handle the truth!!

HAHA, Ahhh, man I needed that !!!!

 

[D.Hearne]

Stock bottom end, with milled stock heads.

I'll probably not want to mill a new set of heads so I guess I'll have to change out pistons. On second thought, I think I'll just wait and build up that 5.8 that I want.

If you've got a 68 4 bbl 302, buying a set of 58 cc heads, then milling them .030 ain't no big deal. I milled my Canfields .060 to reduce the chambers 7cc, from 64 to 57. Only mod I had to do afterward was slot the intake bolt holes to make if fit. One the Vic Jr. I had first, I had to mill it too, but when I used the heads on my 331, the six pack intake fit without milling. Milling it .030, you won't have any problems that require milling the intake or slotting the bolt holes.

 

[68keyblr]

If you've got a 68 4 bbl 302, buying a set of 58 cc heads, then milling them .030 ain't no big deal. I milled my Canfields .060 to reduce the chambers 7cc, from 64 to 57. Only mod I had to do afterward was slot the intake bolt holes to make if fit. One the Vic Jr. I had first, I had to mill it too, but when I used the heads on my 331, the six pack intake fit without milling. Milling it .030, you won't have any problems that require milling the intake or slotting the bolt holes.

Cool, I'm glad I asked!! Thanks for the info

 

[SoCalCruising]

There is a real-world example (if anything in a mag is "real world") in an MM&FF series that took an older, carb'd Capri (302) and took it to 310rwhp without touching the bottom end. It included a cam, intake/carb and head upgrade. It might be worth a look since it "documents" what you are after. The last installment is on the newstand now.