I am thinking of re-cranking my 256, as it has a pretty good rattle before the oil pressure comes up in the morning. My parts guys start looking a little pale at the prospect of finding me a crak for a motor that was only made for two years, so short of pulling my crank to be welded and re-turned, is the crank for a 292 the same? seems there would be a few more of those around.

thanks

 

No, they're not the same...the 256 has a 3.10" stroke & the 272/292 have a 3.30" stroke. However...

The 272 has the same original bore size as a 256. Sooo, if you use a 272/292 crank, you need to use 272 pistons with the proper compression height...with whatever overbore your block needs, if any.

One thing to remember is that 272 pistons are more expensive than the 292 pistons, so it may be worth your while to investigate as to whether your block will take the additional 1/8" overbore to make it a 292.

All that being said, do you think the crank needs to be welded? If it's still running, there likely isn't so much damage that it couldn't just be turned .010 or .020 & receive new rod & main bearings. Assuming there isn't enough block wear or taper to require boring it, new bearings, gaskets, rings, crank turning, & a decent valve job would be around $500 for quality parts, perhaps less. Hope it helps...

 

you can get .040 bearings without a problem.

 

thanks, I'll probably run it for awhile, and see what happens. Someone gave me this dump truck which otherwise seems to run fine and has provided many fine hours of tinkering time. I have a weakness for old junk and this is my second y block dump truck. had fun putting a cam headers and four barrel on the first one which has a still gutless 239, but I drive and work the crap out of it frequently........