what is it?
 

I have a small block Chevy cast iron manifold part number 3973483. The last digit could also be an 8. (the number is not cast very well). I have searched the NHRA spec sheet but did not find any manifolds ending in 483 or 488. Anybody know what this piece was used on?

Re: what is it?
 

Dave, i have run in to this in the past, a lot of the truck manifolds never made it in to the NHRA spec sheets!

Re: what is it?
 

Some of your larger truck intakes, even '73 and later, due to the size exemption of larger trucks,such as 3/4 ton and larger, had no EGR valve provisions. These intakes would never have shown up in any NHRA specs because they never raced any of those vehicles they came on. Trucks that size aren't in the guide, and that resulted in manifold,block and head cores that don't appear in the usual places.I one time saw a non-EGR low profile 454 intake on a big block 71 Chevelle that had a cast date of sometime in '78. Of course, it was an incorrect number, but they were bracket racing it,anyhow.

Re: what is it?
 

According to Alan Colvin's book, #3973469 was a 1971 4bbl Rochester manifold for a 350/270 used in all models.

Jim Henderson
J/S 1029

Re: what is it?
 

Woodro, I thought it may be a truck manifold but Jim may be correct that the last numbers could be 469. I will have someone with younger eyes check it out. Thanks guys for your help.

Re: what is it?
 

Dave, when you're rechecking those casting numbers, check the date numbers that are cast into the top of the manifold as well. Knowing when it was cast often goes a long way towards figuring out what the manifold was originally meant for. I've run into many mystery manifolds and they were almost always from a truck application. Some were also "Made In Canada" pieces that weren't in the guide.