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-   -   L 78 rebuild (https://www.yenko.net/forum/showthread.php?t=89628)

sztuty 12-06-2006 05:27 AM

L 78 rebuild
 
Dear Gurus
In the process of rebuilding my 1968 396
The motor is in great shape, stock bore, etc
M22 tranny, 373 12 bolt, etc
I am thinking I want to step up the cam a bit
My Nova is a true L78 car, all numbers match etc
Want to have fun and protect its value
Any advice/ opinions would be great
Ty https://www.yenko.net/ubbthreads/imag...lins/smile.gif https://www.yenko.net/ubbthreads/imag...lins/smile.gif

Hotrodpaul 12-06-2006 03:50 PM

Re: L 78 rebuild
 
If you are going to keep it original with stock manifolds I would stay with the L-78 Solid cam from Crane. It sounds good and works well with stock manifolds. With headers, I would step up to one of the solid grinds from Comp Cams possibly an extreme energy version with 230 to 240 dergrees @ .050 and .540 to .560 lift. Dont forget a good 3 angle valve job on the heads while you are in there. For an L-78 car, you gotta have that solid lifter "rattle".

Paul

Chevy454 12-06-2006 08:06 PM

Re: L 78 rebuild
 
The blueprint cam from GM/Crane is the one to buy...there are lots of other places to look for power before that cam starts holding you back...https://www.yenko.net/ubbthreads/imag...ns/burnout.gif

sztuty 12-07-2006 01:24 AM

Re: L 78 rebuild
 
Thanks for the info
I am running Hookers, and will go to the step up
Appreciate the specs
Ty

sztuty 12-07-2006 01:26 AM

Re: L 78 rebuild
 
Thamks
I appreciate everyones thoughts
I have always been into small blocks, I want to do it right the first time
Ty

Chevy454 12-07-2006 01:41 AM

Re: L 78 rebuild
 
That GM/Crane cam would be a monster with headers also...a local truck puller here ran a spec LS6 in the modified stock(?) class, with large tube headers, and that thing was a monster...he's since turned one of his dated LS6s into an LS7, and has successfully ran that combo for several years...

Chevy454 12-07-2006 01:46 AM

Re: L 78 rebuild
 
What are you looking to do with this car? You're asking about a cam here, a firing order swap in another thread, but mention you're sticking with the original block and other original parts...?

By sticking with the bone stock original parts and keeping the compression at a safe 10:1 you could easily see 350-375hp at the wheels...step up the compression a bit and 400+ at the wheels would be a no brainer.

sztuty 12-07-2006 01:47 AM

Re: L 78 rebuild
 
Rob
Are you talking about the direct L78 replacement cam that Crane offers?
That is what the machinist wants me to run, and I have the tendency to go the next step up
Ty

Chevy454 12-07-2006 01:52 AM

Re: L 78 rebuild
 
Yep...that's what we run in our all L72s, and what all the L78/L72/LS6 guys in our class run...it's a GREAT cam. We've tickled 116mph in our 3750 *Pure Stock* Y-Camaro...the thing's makin' some beans...

JRSully 12-07-2006 03:03 AM

Re: L 78 rebuild
 
My 70 L78 was rebuilt dead stock (.30 over) with factory (and verified) 11;1 compression and NOS Factory L78 cam put in it, dead stock orig heads (hardened seats,factory size valves)dead stock original Holley 4557, dead stock orig distributor and headers, dyno'd (racing fuel) 422 HP at 5900 just about 400 lbs torque. Engine builder said headers probably added 20 hp + -. There you go SULLY

P.J. 12-07-2006 03:15 AM

Re: L 78 rebuild
 
Dead stock for my 70 L78 chevelle ,lots of power smoke the tires at will.
and its all to original specs.
Best vallue if you are ever going to sell.
PJ
https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

sztuty 12-07-2006 07:08 AM

Re: L 78 rebuild
 
Sully
Thats exactly what I wanted to hear-a direct testimony
I am going to go with that GM Crane cam and use roller-rockers, stainless valves, etc.
I am running a 780 Holley (aftermarket) with the stock distributor with the electronic point replacement unit
If you are doing 400plus horse that makes me happy in my Nova
great info
Ty https://www.yenko.net/ubbthreads/imag...mlins/cool.gif https://www.yenko.net/ubbthreads/imag...mlins/cool.gif

Chevy454 12-07-2006 07:19 AM

Re: L 78 rebuild
 
sztuty: we dead an exact copy of a factory build on one of our L72s...crappy TRW pistons, didn't deck the block, heads left alone except for seats/guides/valves etc, GM/Crane blueprint cam, original 780 Holley...we cc'd everything and it came in at 10.2:1 compression, just like the factory. Anyway, we pulled just a shade over 425hp...we spent a whole day playing with it on the dyno. Thing ran on pump gas, and picked up some HP once it really got broke in...on the other hand, our 12:1 L72, with good pistons, the same GM/Crane cam, and a blueprint, will almost put that to the rear wheels! https://www.yenko.net/ubbthreads/imag...ns/naughty.gif


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