Re: [AMC-list] 360 "strokers" using a 401 crank

[Frank Swygert <farna@xxxxxxx>]

You can search the AMC-List archives from the home page, but will probably find more of what you want at the AMC Forum (www.theamcforum.com). Mostly racers there.

My opinion? You can build a stroker using a 360 block and 401 crank, but remember that the 401 block has thicker webs for more strength. The bottom of the bores have to be notched to clear the crank throws/rod bolts -- they are notched at the factory in the 390/401. 

If you're building a low compression (no more than 9:1) "grunter" (using the longer stroke/additional cubes for more low end torque) you should be fine. If you're building a drag race engine and running high compression I'd look for the stiffer 390/401 block. Don't bore the 360 any more than necessary and it should be okay even at 10:1, but don't bore it to the max then expect it to hold up long term with a 401 crank. 

I don't have experience building such a stroker, so all the above is theoretical. I'd want as much strength left in the block as possible, hence boring no more than necessary. Since it's already being stressed with the longer stroke, I wouldn't increase compression much either. With a 0.030" overbore and 9:1 compression you should still have a reliable engine that will last. That's the way I prefer to build an engine, not strained to the limit. Boring to the max with 10:1 compression and a 401 crank would be pushing the block a bit. If you do that, filling up to the bottom of the freeze plug holes will add some strength back to the bottom end without affecting cooling, but the bores will still be a bit weak. 

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Date: Wed, 5 Aug 2009 00:27:11 -0400
From: "Rocky Lear" <lear31@xxxxxxxxxxxxxx>

Ok guys, is there some place online with a compiled, step by step, shopping list and machine shop procedure for swapping a 401 crank into a 360 block? I have a 401 crank but I don't know if I should forget going the stroker route or not. Offset grinding and SBC rods are not a problem. Chances are I'll have to have custom pistons made even if I go with an overbore of the 360 because of compression and forged requirements. So.... if I have to go custom...might as well do a little more, spend a little more, and gain a LOT more cubes. Has anyone run the numbers of the maximum overbore and stroke CID using a 360 block and 401 crank...offset ground or not. Any help is appreciated.

--
Frank Swygert
Publisher, "American Motors Cars" 
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