Thread: cylinder head question

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Well depending on the head casting there was not much difference between the GT and std FE heads. The GT exaust bolt pattern was different and maybe a slight chamber cc difference. Valves were std 2.02 In and 1.55 Ex. Now if you compare these to say the C8OE-N 428 CJ heads there is quite a differnece. Besides larger valves the CJ head exaust port is straighter, bigger volume and higher positioned relative to the head surface. These things combined helped exhaust velocity. The port opening measures almost the same but is postioned differently on the head and the internal passages are quite different. Now you might have been thinking of some of the FT heads. Those did have quite large chambers and smaller exhaust valves. Also the heat crossover is towards the center not offset like FE heads. The FT intake crossover was matched to these heads. These FT heads were common to the 330, 361 and 391. The 360, 390 truck engines were all given the FE style heads and intakes.


G.