I have acquired two B300 vans from the early seventies, both equipped with 360s wearing 2bbl carbies.

As the engines are surplus to my needs, and both were non-runners when acquired, I have stripped one down to free the rusted-in piston, clean up and sell. But I don't know about the heads.

Are the heads on these vans the same as those used on cars of the same era?

We're looking at whether or not aftermarket manifolds and headers might fit.

Can anyone help me with this?

Yes, pretty much the same, accepting the same bolt-on stuff. Of course, truck/van oil pan is rear sump while car is more centered towards the front. Possible minor cam and/or compression differences.

As the pistons are dished, I would imagine compression differences are in that department...

Thank you. That should help me along greatly.

It's been suggested that they should be 'J' heads, is this likely?

Not possible if still stock, to many years between the making of those vans

I have no hesitation in saying they're still stock...

Both vans are the same, they've never been pulled apart until now.

What do you mean by 'too many years...'? They are only a couple of years apart, probably a '73 and a '75.

Mopar small block head casting numbers

"J" heads are 915 castings. Other, later heads are similar, but have different casting numbers and no letter.

Thanks for the help

I will see if I can find a casting number...

Casting numbers are 348915A on one engine.

Two different numbers on the other, it would appear that a head's been changed as the valve sizes look different. Numbers are 4027163 (with the smaller valves) and 4027596.

OP, the 915 heads came in two different versions in 1971 to 1973, big valves on the 1971 340 motors and with the smaller valves on the 1971 to the 1973 360 and the 1972 and 1973 340 heads
they were not set up for non leaded gas also

Thanks for that... very helpful.



Lots of heads of that era weren't it's almost a matter of course to get hard valve seats fitted in anything that age here.