Early 360 blocks
- Thread starter Dan0954
- Start date
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fishy68
Tyr Fryr's Inc.
Well I'm not sure if that's exactly the proper way to say it but the very first 360's were thick wall castings. They were basically 340's blocks that were's bored out as much but they have larger mains than 340's. There's alot of controversy about when the 360 thick wall castings ended. I used to hear they ran all the way through 72 but recently I've heard reputable engine builders say they have sonic tested blocks and found even 72 360 blocks weren't thick wall so your best bet if your looking for a thick wall 360 is to get a real early one and keep your fingers crossed and have it sonic tested before you bore it out.
Incedentally sonic testing should be done on any engine before boring it over .020 in my opinion.
Incedentally sonic testing should be done on any engine before boring it over .020 in my opinion.
If they can sonic check and OK a 318 block to go to 4 inchs,.........
moper
Well-Known Member
They used the same casting molds and cores as the 340s, yes. So, theoretically, they should be able to go as large in terms of bore sizes as a 340..4.10 max as opposed to 4.06 max. The problem is core shift. If a block is sonic checked, you can see that there are a ton of inconsistencies in the wall's overall thickness. A "thinwall" later casting may be thick enough to bore larger, while some 340 may not have enough meat to safely go more than .030 over themselves. You dont know until you look. There is no "definate" with anything Mopar..
Thanks for the replies. I guess I'll start with the earliest I can find.
I have the time to search and not grab the first thing I find. We have
some old yard's around here and looking around is fun.
This will be for my grandson and I just want a good foundation not
largest overbore. I do have access to an industrial sonic tester so
I can know what I have. To bad you can't check before you buy.
Danny
I have the time to search and not grab the first thing I find. We have
some old yard's around here and looking around is fun.
This will be for my grandson and I just want a good foundation not
largest overbore. I do have access to an industrial sonic tester so
I can know what I have. To bad you can't check before you buy.
Danny
Mark Nixon
Senior Moments Member
You're looking for casting number 3418496, which was current to the 1974 model year.
As far as thick or thinwall, that can happen with any casting.
Unless you're building a mega-horsepower stroker, no one casting number is really better than the next, but a first generation casting (as the '496 block is) will likely be a better choice.
Mark.
As far as thick or thinwall, that can happen with any casting.
Unless you're building a mega-horsepower stroker, no one casting number is really better than the next, but a first generation casting (as the '496 block is) will likely be a better choice.
Mark.
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