So I recall that a few years ago 5.0 Mustang & Super Fords magazine did an article using a 347 in which they compared the results between 1.6 and 1.7 ratio rocker arms. On that particular motor the combination that produced the highest HP and torque (I think) was 1.6 on the intake and 1.7 on the exhaust.
I know the GT40X heads aren't the best, but they're not bad either. However, I've read that they lack a little bit on the exhaust flow. So, with 8 inches of snow outside, I'm thinking about putting 1.7 rocker arms on the exhaust valves to see if that helps the HP and torque numbers. What do you think about that?
I'm thinking that'd be much cheaper and easier than a cam change (which I know would be ideal) or porting out the heads or switching them all together (to AFR).
Anyone done this before?
As an alternative question, those of you with GT40X heads, are you running a combination that you're happy with? If so, what is it?
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1988 LX 5.0 5spd Moonroof
Tri-Ax shifter, CAI, 75mm Granatelli MAF, BBK 70mmTB, 24#, BBK fuel press regulator, RPM II, E cam, Ford Aluminum GT40X heads, Comp Cams push rods, 1.6 SVO rockers, Electric fan, A9L, Diablo Revolution chip, BBK long tubes, 2.5" X pipe Magnaflows no cats, Auburn 3:73 gears, Strange axles, lowering Ford C springs, bump steer kit, BBK rear control arms, Eibach sway bars, sub frame connectors. Cobra R hood. 140mph Speedo. Dynojet = 287rwhp & 302rwtq.
i've heard of alot of guys running mixed rocker sets with 1.7 or 1.72 on the exhaust with good results..if you go ahead with the plan..one big thing though..
how do you plan on checking your PTV clearance without removing the heads?
also are your valve springs up to the task of being able to handle an extra .030" or so of lift? 1.7's with an Ecam works out to roughly .529" valve lift
and there is hidden power and tq in your bottom end,you'll find it as soon as you get rid of the ford racing parts lol
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92 lx 5.0 vert-,stock plastic airbox,stock T-5,shifter & clutch,stock 19lb injectors and fuel pump,no radio,speakers or cruise control..antenna delete(for less wind resistance)
(new)best so far 12.712 @ 105.99mph 1.752 60ft
how do you plan on checking your PTV clearance without removing the heads?
also are your valve springs up to the task of being able to handle an extra .030" or so of lift? 1.7's with an Ecam works out to roughly .529" valve lift
Oh man! PTV clearance. Very good point. At that point I may as well remove the heads, sell them for whatever I can and buy the AFR 165s. Given the amount of labor that's involved. AFRs would propbably be a better return on my money than porting the GT heads.
I'd have to double check Ford's website but I believe that they say the GT40X springs will handle the additional lift.
Thanks for the reality check!
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1988 LX 5.0 5spd Moonroof
Tri-Ax shifter, CAI, 75mm Granatelli MAF, BBK 70mmTB, 24#, BBK fuel press regulator, RPM II, E cam, Ford Aluminum GT40X heads, Comp Cams push rods, 1.6 SVO rockers, Electric fan, A9L, Diablo Revolution chip, BBK long tubes, 2.5" X pipe Magnaflows no cats, Auburn 3:73 gears, Strange axles, lowering Ford C springs, bump steer kit, BBK rear control arms, Eibach sway bars, sub frame connectors. Cobra R hood. 140mph Speedo. Dynojet = 287rwhp & 302rwtq.
GT40X Heads, E cam, and rocker question 
