455 Heads
 

Was wondering if a pair of 455 heads 1970 stamped 15, would bolt right onto a 78 400 without any modifications. Here is the craigslist ad i am looking at for them.

http://norfolk.craigslist.org/pts/1742099040.html

yep

next question. are they worth the money or should i just stick with my 6x-8 heads?

another question. i was just comparing valve sizes of the 455 heads to the heads i have now. the 455 15 code heads have 1.96/1.66 vlaves. also 87cc. the 6x heads have 2.11/1.66 and 7.6 cr. Can someone please break this down for me. How much better are the 455 heads than the 400 heads?

Depends on what you want to use the car for.

15's are small valve heads, 6X's are large valve head although they have a larger combustion chamber than the 15's thus lower comp ratio.

The line in the ad "been sitting for years ready to use" would worry me. Best to look them over REAL good! But then again, who knows what kind of hack job some unknown machine shop or Joe Blow did to those 15's. If it were me I'd pass on them......my .02

yeah that worried me too. so with the 15's i would get more compression and more power out of them? Eventually i am wanting butler performance to build me a 467 motor out of my 73 400 block. Not planning on putting any blowers or anything. And if he had all receipts for the job that was done to the heads that would make me feel better.

Technically yes........but not enough for you to feel any difference.

The 15`s will have press in studs vs screw in for the 6x. The 6x will have all the exhaust flange holes drilled and tapped vs the end holes missing on the 15`s. The 15`s will prolly be missing the lower, long alt. mounting bolt hole as the alt/ps brackets changed from `70 to `71 and later.

oh ok, i guess i will pass on em.

If you`re going to stroke the 400 later, then i`d keep the 6x and have them ported.

X2 on pass