Engine Camshaft Question

durkzz801

Member
Nov 19, 2020
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Albany Ga
I have a 5.0 out of an early 90's mustang that I am building to go in a 65 Falcon. The engine only had about 30,000 miles on it so the machine shop recommended reusing the stock forged pistons due to not needing to be bored. I have a set of GT40P heads that are at the machine shop getting a valve job and setup for the cam that they recommended me going with. I looked up the specs and can't find it anywhere so I called the shop and he said it is a custom grind that he has done up for near stock 5.0's. Specs are Duration @.050 214/220, LSA 112, Lift 482/496 w/1.6 and 513/527 w/ 1.7. I am needing some advice on how this cam will act with the 1.6 vs 1.7 rockers. Car will use the mustang AOD and has 3.73 gears. I just can't find a grind close to it that I could do some research to compare. Any advice on which rockers to go with and if I will need to use anything other than the stock converter?
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
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If you are going for a nice street performer, that cam will work well with what you have.. Use the 1.6 rockers as over 500 lift seems to be too much for the GT40P heads, at least thats what I was told and what the research said.. I just went through this with a new engine ( not fired yet) and used the TF stage 1 cam.. I think mine will have a bit too much duration for me... Your duration specs look good to me.......
 

KRUISR

5 Year Member
Apr 16, 2015
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The factory valve springs on the GT40P heads are not even good for a stock HO cam. Valve spring upgrade definitely needed.

That cam looks similar (not the same) as a Crower 15511(Dur @ .050” Lift: 218°/224° RR: 1.6/1.6 Gross Lift: .468”/.486” LSA: 114° RPM: 2200 to 5500 Redline: 6000). Durations are close but your cam has a bit more lift. Should work nice as a street cruiser/driver.

I have a Crower 15512 (Dur @ .050” Lift: 222°/228° RR: 1.6/1.6 Gross Lift: .496”/.512” LSA: 112° RPM: 2400 to 5700 Redline: 6200). I had a stock AOD (with Lentech VB) and 3.73s for a couple years and enjoyed its manners so you should be no problem.

You could go with either rockers. I have a set of 1.7 RR Crane pedestal rockers (brings my lift to .527/.544).

Here is a sound clip of my GT40 3-bar headed and Crower cam at idle.

View: https://www.youtube.com/watch?v=IKXOE5GYj4U
 
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durkzz801

Member
Nov 19, 2020
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Albany Ga
Thanks! When he ordered the camshaft he also got the springs with them. If it idles like that it will be great. I mainly don't want to have to deal with a really lumpy idle and the issues it can cause with the EFI. I bought an 89 F150 that the previous owner had put what he called a 3/4 cam in. Wouldn't idle and would barely get out of its own way. Took it to a tuner and he said cam needed to be changed it I ever wanted it to do anything but sound good. Swapped it for a stock camshaft and thing ran great. Never want to go through that again
 
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limp

wrap a little cheese around it and its a done
Oct 4, 2020
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I used Alex beehive springs on my "P" heads
DSCF0824.JPG
 
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