I'm wondering why I couldn't just offset grind the crank and use the 292 rod, but mate it with a 261 piston, which would end up about 0.016" in the hole. Compression would be about 9.5:1, without decking the block or milling the head. And, since both the 261 and the 292 use a 0.927" piston pin, shouldn't they mate without modification? Or is there another difference I'm not aware of? Looks good on paper, and is probably as close as you can get without having to resort to custom components. The only reason that the Caddy pistons were used was to get the maximum displacement using "off the shelf" parts, but it isn't necessary to use them.
Any other reasons this wouldn't work? (Rod to piston skirt clearance?) With the GMC rod swap and no stroking, there is random rod to camshaft contact, so with stroking the crank, this is also something that needs to be checked. Also, counterweight clearance for the piston skirts should be checked also.
Thanks for any insight.
261 Caddy 261 stroked 261
Bore 3.75 3.80 3.78 (+30 Pistons)
Stroke 3.938 4.125 4.125
CID 261 281 278
Head Volume cc 95 79 79 (848 head)
Swept cc / cyl 712.7 766.6 758.6
Compression 7.13 9.08 9.49
Piston comp height 2.036 2.007 2.036
rod length 6.813 6.76 6.76
1/2 stroke 1.969 2.0625 2.0625
total 10.818 10.8295 10.8585
block height 10.875 10.875 10.875
piston below deck0.057 0.0455 0.0165
