So, like title says. However, motor in not L98. I'm using a L31 from a 99 burban i pulled since finding out my 86 L98 is locked up good n tight smh. Now car is in fact a 86 Vette. I snagged it for cheap 6 months back. 1st non-LSX car/truck I'm building for myself in over 15 years. So my parts x-ref etc are slacking. Back to the motor.. I already have the offset comp 787-16 valve stem locks to increase cam lift, along with many blue LS3 and yellow LS6 valve springs. I'm planning to use a mild cam. Nothing bigger than lt4. Prefer around .500/.500 with 1.5 rockers. If I didn't have 3 other projects going on at once, I wouldn't be on a budget. So aftermarket runners and intake manifold are out of the question since runners cost more than 243 heads 😂. So I've already started porting the factory tpi which have 2 pre 1987 and 1 of 87+ complete tpi set-up's. So have done the rough porting of Siamese'ing the tpi parts. Opened up the TB hole as well. I already have worked 113s which wouldn't even need the offset comp valve locks. The bowls were already mildly ported also. Screw in rocker studs, guides etc. The springs were doubles good for .550 max lift. I do have couple sets of 062 heads laying around that i already planned to mod and sell anyways. But I don't want to use the 113s as I'm not sure I plan to keep the car.
​​​​​​Now whichever heads I end up using, would going with a bigger than lt4 cam severely hurt performance being no matter how big i port and can get it to flow tpi system to flow, should i cuz the heads can handle a higher than .525 lift? Even if i spend lots of time porting the heads, intake and plenum.. the factory runner will still be a restriction of airflow and not efficient in higher RPM's.
Does anyone have a similar set-up and what cam are you running?
Thanks in advance

 

A stock runner pretty much dictates a peak hp in the 4500 range. Cam duration under 220. Anything more is relatively pointless. I'm not sure what information you'd be looking, sounds like you have a good grip on what you're working with.

 

LPE 211. Ported 113 heads, base, runners, plenum. I picked this cam after sound advice on this forum many years ago. Improved the mid range and seemed to pull nice into the low 5000's.
It would rev to 6200, but seemed to stop pulling well below that. No regrets with that cam.