I finished up my cam swap on my 83 Z-28 earlier this week. It idles good and drives good but when I get on the gas the car does not have the power it did before the swap. Any ideas here? My car has the lg4 motor and my mods are Comp Cam XE262, Comp 981 springs, Edelbrock RPM Qjet manifold, Edelbrock TES Headers, 3" Flowmaster exhaust, and a 14x3 K&N open element. I also just put in new plugs, cap/rotor, and coil.

Im thinking it could be

1. Timing- I got it set at 8 degrees advanced right now. Think it needs more?
2. Valve lash- Im pretty sure I have it set right seeing how ive done it over 4 times already just to make sure lol. But this whole swap has been a learning experience so you never know. I don't think I have it too tight, maybe too lose if anything. If the lash is set improperly could that be a source of my problem?
3. Carburetor- I rebuilt the Q-jet during the cam swap. It runs good but maybe I need to fine tune it since I put the new cam in?

What other things should I look at? I am still learning here and the cam swap has definetly taught me a lot but I need some help here.

 

I would check the Q-jet. They can be VERY touchy. Also did you replace the metering rods in the carb when you were done? You could essentially be making one hell of a lean mixture causing power loss.

 

I didn't replace the metering rods. I just cleaned them up with carb cleaner and put them back in. Can I get different sizes like you can do with the secondary metering rods?

Also got a sound clip of my car. Excuse the wires in the engine bay Will clean it up once I get it running right.

http://videos.streetfire.net/video/9...d100eafed6.htm

 

What you need are DR rods from an L69 H.O. application, and a "K" hanger, if I remember correctly. You can also order them from JET technologies, who are also E4ME Quadrajet wizards. Those rods are quite important, I used nearly theat exact package with my L69 and picked up 3 tenths just by playing with the metering rods.

What's happened is you've sacrificed low-end grunt for a 6000 RPM top-end rush. You also need to change your torque converter to get it onto the power curve faster. I found a torque converter was worth close to 4 tenths. Also, set your initial timing at 12 degrees.

HTH, YMMV.

Dan