Do I Need a Bushing for the TC for a 273/318 Swap?

[lead69]

I get it but this has been discovered before. I don't remember where but when we encountered this we searched and found discussions on this with the same results (including this forum iirc). The ones we dealt with were unturned factory 340 cranks that were early 67 with small registers. The assumption is the factory must have carried over the 273/318 cranks small register for a limited number of early 67 built 68 340s. It was chrysler lol, look at the stuff they have done.

 

[cudamark]

I know, but, I'm a born skeptic! I can only go by my own experience until I see proof of something different. A "carry over" from a 273 or 318 doesn't make any sense to me as the 340 used a total different billet. Same bearing specs, sure, but, weight and design is different...and with different forging marks to go with it. I'm assuming you're talking about calendar year when you say early '67, as there were no 340's in a '67 model year. And there again, I've never seen a 318 crank with a small register either, so, what are they carrying over? I owned a Mopar wrecking yard for 32 years, tore down hundreds of small blocks, and the only crank I ever saw with the small register (not counting the slant 6) was the '64-7 273 crank. I'm not saying that it's impossible some weren't made, but, show me one with good photos and some forging marks, or a Chrysler tech bulletin, and I'll happily acknowledge it as a true factory item. A genuine 340 crank will have a hole through the first and last rod journal. Solid journals are 273 or 318.

 

[lead69]

I know, but, I'm a born skeptic! I can only go by my own experience until I see proof of something different. A "carry over" from a 273 or 318 doesn't make any sense to me as the 340 used a total different billet. Same bearing specs, sure, but, weight and design is different...and with different forging marks to go with it. I'm assuming you're talking about calendar year when you say early '67, as there were no 340's in a '67 model year. And there again, I've never seen a 318 crank with a small register either, so, what are they carrying over? I owned a Mopar wrecking yard for 32 years, tore down hundreds of small blocks, and the only crank I ever saw with the small register (not counting the slant 6) was the '64-7 273 crank. I'm not saying that it's impossible some weren't made, but, show me one with good photos and some forging marks, or a Chrysler tech bulletin, and I'll happily acknowledge it as a true factory item. A genuine 340 crank will have a hole through the first and last rod journal. Solid journals are 273 or 318.

Yeah we are aware of all that, wouldn't waste my time posting if we were not. They don't exactly "forge" the pilot in them do they?, wouldn't be anything to machine a run of them for some manual cars with a small pilot for some early 68 340 blocks. I don't really have time to try to prove something to one skeptic, if it's convenient I certainly will post pics. You can chock this up with the whole "all 72 340s have a cast crank" deal or whatever other chrysler anomoly others have encountered.

 

[Scody21]

I saw both of the cranks our buddy has last summer when we were dealing with that. Along with a few other standard cranks from his and my 340 and 318. It’s not really surprising. It’s just like the mystery K frame post from the other day. Why the heck would 2 of us in different parts of North America have biscuit mount pass through sway bar A body K frames? Mamopar was like let’s just pump out the cars and let these jokers figure this crap out in 50 years... LoL