Early Hemi heads

[56 man]

I was checking out Wilcap.com and noticed that they make manifold spacers to use when putting 331 or 354 heads on a 392. I'm going to be building a 392 shortly and I wanted to know why you would put 331 or 354 heads on a 392. Thanks for the help,
56 Man

[Ausydad]

Don't know, but I do have a line on a pair of Desoto Hemi heads of unknown size. If you like, I can research a little. Email me
Ausydad@yahoo.com

[gwaii]

get a copy of tex smiths,the complete chrysler hemi engine manual by ron ceridono.every thing you need to know is in this book and it will definatly help in the build up of your 392.its good reading.

[goose]

The 331/354 heads are higher performance than the 392 style heads. I've read this in a couple different places, but can't for the life of me remember exactly why they are better... I think the performance difference isn't really big.

[56 man]

Thanks for all the help. I'll make sure to pick up a copy of that book.
56 man

[Larry S.]

The 331/354 motors are low deck motors, and the 392's are tall deck motors. They both used the same intake manifolds (with a variation on the front water crossover on the early 331's). To compensate for the difference in deck height the 392 heads intake ports were positioned lower on the head so the same intake would work. Therefore, the 392 heads have a kind of a dogleg in the intake ports, and the 331/354 heads have a straighter port. Supposedly the 331/354 heads flowed better, but some of the old timers that raced these engines claimed that there wasn't enough difference to tell. If you already have the 392 heads I wouldn't go to the trouble and expense to change over to 331/354 heads for what little gain you might get.

[56 man]

Thanks for shedding some light on my problem. I don't want to spend a lot of money for a little gain. Thanks again.
56 Man