:!: I'll bet shoe-lace eating money that the flange on all US, Argentine and pre 1970 Aussie 144/170/188/200/221's is the same.
My machinist did the welding for my crank main bearings (controling fillet radii and shoving the extra 100 thou on it) and width alteration of the offending thrust bearing. The smaller than Windsor/Cleveland crank flange is a pest to fit an FMX drive plate to, because all the bolts are wrong on it...the PCD is the smaller 170/188/200 size.
Don't talk to me about crank pitch centres , main bearing size, thrust bearing width or front crank pulley (harmonic balancer). They are all different to the 250 cross flow crank, and have been a constant source of hassle to me. And the rope seal is a proper mental break down material, which is why I haven't fitted it to the engine. My Chevy pistoned wonda engine has been unassembled in my garage since I arrived in my new house, and spent 12 months under the crawl space in my old house. I'll get there. I'm still working on starter fouling the bellhousing flange on my AOD trans adaptor. Putting a 30 degree slant on things is not a picknic. No pictures yet. I broke my work digital camera in the rain doing site investigations late last year, and my boss is still trying to get NZ$1300 of lost profit back into the company coffers.
And I guess
Aussie7mains and
HotRod would disagree strongly about the 221 being a rod chucker. Even at a 400 Chev-like 1.48:1, the super short stroke and huge overlap in crank pin /main journals means that rod bolts are the only weak link. Rods are close to 289 spec in length, but narrower. I'm picking that Aussie ones are forged...but we've been through this charade before...they are probably cast....doh!
Bill Mann in Brisbane built over 70 GM Holden strokers using the 1967 to 1971 186 Red motor L6 engine. A lot of 221 cranked 186 Holden strokers run 1.425:1 stroke:rod lengh ratios..stock Sunbird rods on a cut up Falcon crank. No reported breakages. Give it death,
addo!