Hi

According to the RPO codes on my 1986 Camaro with a 305 TPI I have heads for a 427 (L89 ALUMINUM CYLINDER HEADS FOR L71), and L71 is 427 CU. IN. ENGINE – 435HP.

I am wondering if this would affect the power output from the 305. It also has short tube headers and a 3" custom free-flow exhaust.

I am just wondering as the engine seems to produce more than expected from a standard 305. I am not looking to change the engine as it is a number matched, and I would like to keep it that way.

 

I think you are misreading the LB9 rpo code.

 

Thanks, the 8 and B both look the same, it would make more sense...

It seems it must just be the upgraded exhaust that is helping.