Olds 371 J2 Manifold, will it fit later motors ?

[55olds88]

Hey,
I had a guy asking after my 57 J2 manifold recently for a 394 will it fit ? I don't really need it for my 324's as it doesn't fit with out modification and I have a couple of alloy ones that do and will sell it to the dude if it fits.

tx.

[yorgatron]

nope.

[38Chevy454]

As Yorg said, no. The deck height is the difference, 394 is taller than the early 371. Later 371 are just small bore 394, but the 57-59(??) 371 are lower deck height. The J-2 was a low deck height 371, will not fit a 394.

[twjoyce]

57 & 58 are the low deck 371's 59-64 are basically 394's. Easiest way to tell is the 59-64's have 5 bolts around the perimeter of the valve cover and the 49-58's just have the two down the middle.

[Blownolds]

You might get it to fit with spacer plates, but that's going to be the only way. Also the ports on that J2 intake are smaller than on the 394's. So if doing a 3x2 on a 394, may as well use an Offy.

[55olds88]

Thanks Y'all, I thaught I was right when I told the guy it wouldn't fit warlier in the year....