I was considering upping the measly LG4 with better flowing L98 heads and bigger L98 cam and some non-AIR headers. My question was: will the L98 heads and cam feel comfortable in my LG4? The LG4 is in a '90 Firebird, but it's an '85 Trans Am LG4. What about the cam? I'm not really looking for a burner motor, just something to scoot me along a little faster. If this combo is to work, how would I tune the carb?

 

I wouldn't bother getting a different set of heads. Your current heads with 1.94" intake valves and basic port clean-up will flow as well as the L98 heads. Plus, the L98 heads will have the center two bolts at a different angle than your intake manifold, and will need to be shaved to bring the chamber size down to 305 size.

Most any mild computer-compatible cam should do.

What have you done for exhaust? Air cleaner? Those are restrictions that should be addressed before any thought is given to cam or heads.

 

For exhaust i have a 2.75" mendrel bent single through with a cat and flowmaster muffler, im going to adda shorties later on. For air, I'm running open element with a summit (K&N rip-off) X-filter.
I was wondering about hte L98 cam (chose it because i got it for free) because it wouild be from a next gen block (86+), would that cause problems?
Thanks,
-Matt

 

Yes, the later cams are factory roller lifter types. Although they can be made to work in non-factory roller blocks, it isn't pretty - and probably not worth the hassle.

 

Back to the drawing board then, I suppose

 

First do the exhaust - you will be surprised how much power you will pick up. Then a dual snorkel intake, EGR intake manifold. underdrive pulleys, electric fans..... all bolt ons that will give you 210hp+.

 

The '90 should have had electric fan, unless they swapped over the engine driven from the '85.