Well, I don't own a Chevelle guys, but this is probably the best Chevy forum site out there, and I do own a '90 454SS truck and have a lot of cam questions with the following engine-
GEN 6 BBC 454 Stock shortblock (1997 I think)
Vortec L29 Heads 99cc chamber volume (small ovals) Further Head specs-
Intake Port Flows
CFM @ Lift
Valve Size: 2.065"/1.725"
Chamber Volume CC: 99cc
Spark Plug Position: Angled
Spark Plug Size: 14mm
Spark Plug Reach: 0.708"
Spark Plug Number: RS12YC
*L-29 exhaust port = 81.2cc.
*L-29 intake ports = 233.2(S) and 239.5cc(L).
Stock L29 Cam Specs-
Camshaft type: Hydraulic roller Camshaft lift (in).480 intake / .483 exhaust Camshaft duration (@0.050-in)204° intake / 209° exhaust
Anyways, my question is-
I'm in need of a cam. It has to be a hydraulic roller and make a descent improvement in power, but not so much lift or duration that there is a danger of hitting the piston with the valves or requiring changes in the valve train such as rocker stud or spring changes. Yes, I said not even spring changes, so this would be a mild cam, if you haven't already gathered that, with an RPM ceiling of say 5,500 max. I know the factory heads have a limiting net-lash set up, but I don't want to mess with the valve train, not even springs. I do not care about the idle quality, emissions, or whether the cam is computer compatible. I do care about improving power, keeping it a hyd roller, and piston to valve clearance. I've heard good things about the XR276, but I have also heard that the max lift on these heads is .500. The truck weighs 4300 lbs, has a TH400 with 2,500 stall, 3.73 rear end, dual cat free exhaust with long tube headers, no computer, dual plane intaKE with dual Edelbrock AVS 600s. I've also been looking at the following GM cams and was wondering if anyone had any experience with these:
ZZ502/RamJet 502 cam
Camshaft type: Hydraulic roller Camshaft lift (in).527 intake / .544 exhaust Camshaft duration (@0.050-in)224° intake / 234° exhaust
Camshaft type: Hydraulic roller Camshaft lift (in).510 intake / .540 exhaust Camshaft duration (@0.050-in)211° intake / 230° exhaust
Oh, one last thing, if someone could ballpark an hp and tq estimate for these cams that would be great, stock the truck makes 290 hp, and I think 410 tq.
-Thanks for the help and for reading my novel guys.