312 rear main

[Ray]

most of the guys I know out here convert to a neoprene seal or simply bore out a 292 block since the sleeve used for the 292's was generally the same as a 312. the 292's used a neoprene seal originally.

[hiball3985]

most of the guys I know out here convert to a neoprene seal or simply bore out a 292 block since the sleeve used for the 292's was generally the same as a 312. the 292's used a neoprene seal originally.

?? I've torn down many original 292 and have never seen a neoprene seal. I've only seen people turn down the 312 crank mains to fit the crank in a 292 block.

[jumping jack flash]

Reading this thread made me feel talented. I used the rope seal in all Ford engines, and never had a leak. I'm with you Hi-Ball. I never have seen a y block with anything other than rope.Other engines that use rope are Oldsmobile. I worked in a research lab that tested oil, using 302 Fords, and 425 Olds. Rope seals was all we ever used.When they quit using these engines , I finally looked around for another job. The 302 was replaced with 2300 Pinto engines, and the Olds 425 was replaced with the 350 olds. No more fringe benefits.