I know it's not smart to keep these poor stock heads, but at the moment I have to spend a lot on other parts of the car. I have a blown head gastket and two flat tires, no shifter, and expired stickers. But my new plan is to port/polish my stock heads and install the LT4 cam. The specs on the cam are: I 203 / E 210 @ .050 lift / 476 Intake Lift, 480 Exhaust / 115 lobe center. That is with 1.6 RR's, I have the stock 1.5's with stock springs. Wouldn't the 1.5's bring down the lift and make cam more mild....enough so I could keep my stock springs for now? I don't have the money to change springs right now, but it will happen soon when I swap in my 350shortblock and buy some vortec heads. Thanks for any info.

 

I think you will find disappoining results with those '187' heads. The 305 TPI heads are extemely cheap if you can find some. You can usually get some for less that $100.00. YOur gains with these could be very noticable.

 

I have a #416 head, but only one. Are those the TPI heads? If not, they should still work better than 187 heads right?

 

The '416' casting number is a pre-87 TPI head. Just put them on my car. Will flow much better than the TBI (187) heads. If you can pick up another you will be much better off.

Also the '081' casting is also the 305 TPI head but it the after-86 version. The difference is the 4 bolts on the top of the head. On the pre-87 head they are angled.

 

Just noticed you have a '91 Firebird. If you go with the pre-87 heads you will have to bore out the 4 center bolt holes in the '91 intake manifild. Basically you will have to make them oval instead of round so the bolts can reach the threaded holes on the head. The intake is aluminum so a drill and good bit will do the job.