L48 "upgrade"


Mar 23, 2008
sunny Florida
What's a good L48 "upgrade" ? Let's say someone has a L48 (1974-1979) that is known to be a low performance engine ?
I used to run a L48 bottom with flat top pistons and 64cc chamber heads. The previous owner installed a Edelbrock RPM cam with 234/244 dur which was too much for the (still) low compression ratio..... I replaced the RPM cam with a very mild "performer" cam and it worked really well.
Specs: flat top pistons and 64cc heads: roughly 9.5:1CR, cam 194/204 dur, performer intake and performer 600cfm carburetor.
The engine fell flat on its face at 4500rpm but with the trans go shift kit it really wasn't all that bad, felt like 50hp more than it would actually put out.....
I believe that setup was close to 380 flywheel HP, 300HP at the wheels assuming 20% drivetrain loss.... what do you think ?
What do you think is realistic with a better cam (the performer is a truck/rv cam )???? What about a Summit 1104 (cheap) or similar cam with 214/224 duration ??
Last edited: