im going to rebuild my 89 rs in a couple weeks.... im going to swap out the cam for a lt1. what would be a good set of CHEAP heads to put in?? 305 tpi? L69? or should i just port mine? help!!!!

 

I believe TPI and TBI heads would be the same. I was told to expect at least 15% better flow out of my stock heads with some porting and unshrouding of the valves. I think the extra money is better spent on headers. I guess I'll know if I made the right choices when I turn the key!

 

The TPI and TBI heads are not the same. There are major differences.

Sublime: Try a search on this topic. There has been a lot of good discussions about this lately.

In short, the stock heads are usless without a lot of porting. While reading the previous threads, look for references to a "swirl" in the intake port.
Come back with a specific question, and one of us will happily answer it.

 

dont port the stock heads. for cheapness i would get some TPI ones and try to do some porting on those if you want

 

If you have access to the TPI or L69 heads for cheap and they don't need a rebuild then just take your pick, they are the same, no differance, nada, none. Of course aluminum L98 heads would do ok too.

Steve

 

Thanks for catching my mistake!

 

The most common 416 castings (L69, LG4, LB9) are the best factory 305 heads for performance. If you want to go cheap, then nab yourself a set of these. Unfortunately though they are perimeter bolt style heads that dont retain the valve covers as well....
The 081 87-92 LB9 heads are based on the above runners with slightly improved combustion chambers and have the about the same power increases. They have the centerbolt holes.

There are major differences between the 187 (L03) and above 416,081 castings. There are cast in swirls before the intake valves. There are valve shrouds in the intake runners right before the intake valves. The 187 heads are a good midrange torque building head, excellent for towing; and not a performance casting.