Camshaft upgrade for '77

[clarkwood]

I am looking into modifying my '77 L-48 to bring it into the 300-350 hp range. I am looking at specs for different cams which should bring it into that range (when used with new manifold, carb, heads, and exhaust). Where can I find the specs on my stock cam for comparison?

 

[Dave L.]

cam specs for an L48

clarkwood- I can post that info here in the morning when I get to work.I have all that info at the dealership.

Dave

 

[Dave L.]

cam specs for L48 cam

clarkwood,here is the info you need......
Original GM#3896929 cast 3896930 current GM#14088839

Duration ----- Lift
int- 310 int- .390
exh-320 exh-.410

Dave

 

[vette-dude]

Is your vette an automatic or stick? Also pay attention to the lift specs on the cam you select as there is a limitation due to valve bind. I can't remember but think that stock height limits you have is .507 before bind. My 383 stroker motor had stock valve springs and the most cam I could safely get away with was in the .290 range. I had to put in a stall convertor (started with 2,500 stall and ended up with 3,500 stall). The 3500 stall was used only for drag racing but it will work on the street. I used TCI but there are others out there. Try to figure on everything working together, i.e. carb, manifold, cam, compression ratio, stall convertor, curve in distributor, and size of valves. Comp Cam in Memphis can figure all this out on their computer if you can give them the info they will need. I think they have a website and this info may be available there. Also Summit racing is another good source for help in blueprinting your motor. ( I have no stock in either company!!) If I can emphasis one thing-- Bigger is not always better. All components must match each other and work together. Determine what you are going to use the car for before you start the rebuild or adding components. Now I'll shut up.

 

[JohnZ]

Those are "advertised" duration numbers - the comparison numbers, at .050" lift for the "929" cam are:

Intake Duration - 195 deg.
Exhaust Duration - 202 deg.
108 deg. intake centerline
116 deg. lobe separation angle

 

[clarkwood]

Thanks for the advice. I think the best thing to do is have someone give me a blueprint to follow to match components.

 

[555]

Clarkwood,

What heads and intake manifold are you looking at to buy? Carb choice as well and we can start to set you up.

Forgot,,is yours a automatic and what gears do you have?