354 TRUCK HEADS...

[HARDTOP]

Hi guys,
I am new to the forum and I am wondering the difference in valve sizes between 354 truck and car heads. I know that there are no water crossover openings in the truck heads and that the heat riser is taller. I have heard from some that the truck heads have hardened exhaust valve seats installed from factory and that the valves and ports are the same size as a 392. Any help would be much appreciated and will guide my next hemi purchase. Thanks.

[wayfarer]

Valves are a bit smaller, the exhaust also uses sodium filled stems and rotators. The heat 'riser' is part of the cooling system.

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[HARDTOP]

So, when I upgrade to bigger valves, are the 2.0" valves too big for a 354? I know a performance chev 350 usually has 2.02 intake valves and 1.94 exhaust, but hemi's are supposed to breath alot easier. Are 2.0" valves too big? I don't want to give up all of my low range torque as this will be a street engine.

Thanks for the help!

[wayfarer]

Yeah, don't try to compare the Hemi to other lesser engines...lol
The stock 354-392 valves are 2.0 x 1.75 and will do everything you need on a street engine. Keep in mind that the stock sodium filled exhaust are about 7/16" dia so new guides are a given.


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