gears and converter for an L78 cammed big block

[GreenLS6]

I Extensively test and dyno with the LS6/L78 cam.. with the Oval port heads and Manifolds in a 454 with 10.1 comp and a decent intake. you should have 525ish ft. lbs. of torque. DO NOT ADVANCE that cam in a 454 or it WILL NOT pull past 5000 rpm.
If your repro cam has the 114 lobe separation RETARD 2* ..with the oval ports it will loose No torque but will pull to 6200rpm.. minimal loss to vacuum.
Don't be afraid of the exhaust manifolds - I have made way more power than you think in my Pure Stock motors and pull to 7k + in my L89/396 ... 6800 rpm in my LS6 making North of 550hp with UNPORTED HEADS AND MANIFOLDS.

consider a Yank 11" convertor , they work nicely.

[earntaz]

Good info Tom -- thanks ... TAZ

[aaronkl84corvett]

Originally Posted by GreenLS6

I Extensively test and dyno with the LS6/L78 cam.. with the Oval port heads and Manifolds in a 454 with 10.1 comp and a decent intake. you should have 525ish ft. lbs. of torque. DO NOT ADVANCE that cam in a 454 or it WILL NOT pull past 5000 rpm.
If your repro cam has the 114 lobe separation RETARD 2* ..with the oval ports it will loose No torque but will pull to 6200rpm.. minimal loss to vacuum.
Don't be afraid of the exhaust manifolds - I have made way more power than you think in my Pure Stock motors and pull to 7k + in my L89/396 ... 6800 rpm in my LS6 making North of 550hp with UNPORTED HEADS AND MANIFOLDS.

consider a Yank 11" convertor , they work nicely.

i pulled the car apart this weekend - 1) I have a new 9" converter from Cliff Ruggles that has a 3200-3400 stall speed - he swears by em - so thats what I went with.

I also had a Crower 01244 cam waiting to go in - i was worried about the LS6 cam being a bit too much for my engine considering i'm not even 100% certain its 10:1 - i'm guessing a bit closer to 9.5:1 which is probably still ok = i just hate being on the line. The crower is a 290/298, 232-244, 562/571 on 112 - and I have Rhodes lifters for it.

As for an intake, i was running the low profile LS5, and now will be running the aluminum version of it which was used on 427/390hp Corvettes... if nothing else, i'll save the 100lbs

when I pulled the timing cover - i checked the LS6 degree at it was indeed advanced 2* so thats right in line with what you said.... but the car just didn't have the "umph" i was hoping for - and i'm certain it wasn't at 500ft/lbs. it would barely break the tires loose flashing the converter at 2400 - barely... you could feel the cam "switch on" right about 3000 rpm but felt flat from about 4800 on up....

fwiw - it was an Elgin E-905p variety - if that makes any difference -

i can knock out a cam swap in a Monte Carlo in about 6 hours - SO, if this Crower is a dud then i'll happily go back to the LS6 - but i think i'd use the Crane or a SpeedPro version as I know they are accurate blueprints- unless i could find an original that isn't junk

will report back soon...

i hope i'm simply not expecting too much from this motor.

also - to be clear - the heads on this are 702 1966 castings and they cc-ed at 94cc.
with the stock 1971 LS5 flattops, and a steel shim head gasket - my math gets me 9.7:1 anyone car to check? stock deck height.

[aaronkl84corvett]

well the Crower 01244 and Rhoads were a bust -
even with the new converter I think the car was quicker/torqier with the 178 cam advanced 2degrees,

back to drawing board!

or at least back to the GM cam

[GreenLS6]

Cant tell if any of these pm replys are getting thru..
just call.. tim 517-605-421 eight