Does anyone know the factory specs of the 5.o cam in our cars? ie.- degrees duration and lift/lift? A link or straight up factual answer would be GREAT! And even more better if you can tell me what they are on an 88 H.O.! See, I got a good buy on a set of GT40 heads and they have 1.72:1 FMS roller rockers on'em. Now what I'm tryin' to figure is ARE MY PISTONS GONNA MASH THESE SHINY NEW VALVES since the rocker ratio is a smidgeon higher? I'd really like to hear from someone who's done this, or the bonafide genu- Ine specs afformentioned above!
i think HO have 444 lift.
.444 lift on all of the HO cams (the SO cam is around .399 lift I think). There were some slight duration changes over the years. I got this from the corral...
85-late 88...210/210 @ .050"
late 88 and up...206/210 @ .050
So if valve lift with a stock 1.6/1 rocker is .7104, would the flat top pistons clear the increased valve lift to .76368 with the 1.72/1 rockers?
HUH????
The .444 lift on the HO cam is with the 1.6 rocker... Actual lobe is more like .278, so with a 1.7 rocker total movement is .472
Do you mean the "flat top" pistons with the 4 valve reliefs that came on an HO engine or the no relief pistons on an SO? I ran GT40P heads that had a 1.90 intake valve with a stock HO cam & 1.7 Cobra lifters on a Mustang HO engine - no problem - I clayed the setup before using it - you should always check clearance - it's the best way to ensure you don't hurt your "shiny new valves" :D
Exactly.
You're yanking the heads anyway, so check your piston to valve clearance while you're there.
If you find you can't run the 1.72s, your factory stamped 1.6s will work fine on the GT-40s (assuming they are pedestal mount).
so i can run the HO cam with 1.7 roller rockers and it will clear fine with the SO pistons?