Ok so I talked my wife to be into going on the HotRod power tour this summer for our honeymoon. I'm going to pull the stock 1989 L98 and go through it (rear main leak and needs valve seals). Motor runs strong and I'm not looking for a race car but I am curious. While the heads are off, if I do some mild blending and bowl work and a three or five angle valve job with an edelbrock intake, runners, some plenum work with a 52mm TB (just cause I have one) headers and a nice 2 1/2" set of duals. What do you think I can realistically expect for improvement. Hp and trq. Should I try a split set of roller rockers (I don't plan on burning a prom) 1.5 and 1.6? I'm reasonably happy with the performance and I like the fuel economy so I don't want to go nuts. Thoughts?

 

If you are going to perform all that modification, you WILL be changing the volumetric efficiency of the engine. While the MAF can accomodate those changes at lower throttle angles and RPMs, you'll probably need to reprogram the fuel at least for best WOT (open loop) operation.

Eventually, you'll get there, possibly only out of need. You don't want to go too lean under heavy load and start melting things.

 

although, I've seen(and done) much more mods w/o chip changes. If you're gonna do all that, put a cam in that thing! Yes, you'll see a nice improvement w/ bowl work/gasket matching, but you should really look into changing that enemic camshaft. My buddies' 87 GTA is running a HSR , bowl blended heads, .030 over, 220/230 @ .050 duration, .497/.502 cam...still on stock tune... - gets 22-23 mpg highway, runs mid 13's...