I know larger valves on stock heads isnt worth and power gains but would that along with a 3 angle valve job be worth any gains?
Thanks



Going on a cc306 mild head work lt1

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1997 Camaro SS #1039 M6
Pacesetter Long tubes, TTL exhaust, No Emissions, Under Drive Pulleys, Mad Z28 Tune, 4:10’s, Level II Suspension, BFG KDW’s. best time 13.3 @ 105, 94 F

 

Some simple pocket porting would probably give you bigger gains.

 

Maybe you should look into what the quality of the factory valvejob is before you get in such a rush to undo it.

 

Larger valves may not show increases on the dyno, but I like having the peace of mind knowing that I have high quality valves in my heads. Seeing how GM cheaped out on so many other parts of the valvetrain (springs), I wouldn't put the stock valves back into heads for any kind of performance application. I went with larger valves since there was no price difference.

 

Yeah, you know, we must have five threads a day about stock valves failing. And, of course, none of the well respected head porters re-use stock valves.

[/sarcasm]

 

Stock valves are known to break with higher spring pressures and combustion temperatures. Performance valves are made out of increasingly stronger levels of stainless and Inconel for exactly this reason.

The stock LT1 heads work very well with a 2.00/1.56" valve combination and porting to take advantage of the larger valves. The factory valve job is three angle - so any shop telling you that alone will give you a performance increase doesn't know what they are talking about. Apples to apples a head that has bigger valves and pocket work to match the diameter will make more power than a stock head even if it is not given the full port work treatment - most power is found in the bowl/pocket work.