Forged 273 crank in an early 360 Block?

C130 Chief said

Anything is possible, but sometimes you have to ask yourself why (especially if nobody else has done this before). First off ALL A series engines had the same width main bearing, the DIAMETER changed for the 360. This was to maintain crankshaft rigidity through journal overlap. A stock 360 or later 340 cast crank was not exactly a weak piece.

Welding up such a crank on all 5 main journals and then surfacing would cost quite a bit if you paid your friendly neighborhood machine shop to do it. Probably near the cost of a rebuildable 340. Plus, if you are starting out with a 360, why spend bucketloads of cash to reduce displacement?

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I misunderstood the information then.

I was not able to find 1 site that listed the dimensions of both the 318 & 360 bearing journals. Do you know of a link that will show that data?

As far as cost, the welding would be the only real expense as, like I said in the original post, there is a crank grinder in the family. This sort of thing is done all the time W/350 SB Chevy cranks that are installed into 400 SB Chevy blocks for the same reason, an internally balanced crank that will rev better.

What kind of $$$ is a rebuildable 340 available for? The few I found on E-bay were in the high price range.

That would be my 1st choice, a rebuildable 340, @ least the block. I have the 273 forged crank, the rest I can gather from readily available modern stock parts.

Barring that, a de-stroked 360 would be next choice. Readily avilable modern stock parts combined W/Keith Black pistons would make a destroked 360 bored .040" over (340) W/a 10.5:1 CR quite do-able. Forged 273 crank, early 360 block/59cc magnum heads/.060" thick headgasket/KB hypereutechtic 340 flat top pistons. The compression hieght of those particular pistons would put me about .048" from the head deck W/the .060" gasket.

If I go the full 3.58 stroke W/zero deck 360 flat top pistons & the 59 cc heads, the CR will be in the 11.3:1 range. Too much for pump gas. The alternative here would be to go 2.02 on the intake valves & unshroud the valves to increase the chamber size to about 66CCs.

Again, the welding/turning of the crank will not be that expensive in my particular case. I think far less than the price of a 340 block.