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early 360 block thickness (sonic test) #760643 07/29/10 08:39 AM 07/29/10 08:39 AM
Joined: Mar 2010 Posts: 162 monticello,ms andy3965 OP member
andy3965 OP member Joined: Mar 2010 Posts: 162 monticello,ms	i dropped my '73 standard bore 360 block off at the machine shop tuesday and the machinest stuck his sonic tester in a couple of the cylinders for a quick look and said "wow you got a good thick block".I asked what the numbers were and he said ".276 thrust .240 non-trust". if these numbers hold true for all the cylinders can it go to a 4.1" bore? i've heard that the early 360 blocks were built on the 340 tooling and could go the same bore as .60 over 340 (4.1"). i don't know how to do the math to find out max bore size. i'm just gonna go .30 over now but would be nice to know that it had 2 more rebuilds left in it. thanks, Andy MOPAR BORN,MOPAR BRED,AND WHEN I DIE I'LL BE MOPAR DEAD!!!

Re: early 360 block thickness (sonic test) [Re: andy3965] #760644 07/29/10 08:49 AM 07/29/10 08:49 AM
Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again Moparnut426 I Live Here
Moparnut426 I Live Here Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again	Quote: i dropped my '73 standard bore 360 block off at the machine shop tuesday and the machinest stuck his sonic tester in a couple of the cylinders for a quick look and said "wow you got a good thick block".I asked what the numbers were and he said ".276 thrust .240 non-trust". if these numbers hold true for all the cylinders can it go to a 4.1" bore? i've heard that the early 360 blocks were built on the 340 tooling and could go the same bore as .60 over 340 (4.1"). i don't know how to do the math to find out max bore size. i'm just gonna go .30 over now but would be nice to know that it had 2 more rebuilds left in it. thanks, Andy Why waste your block for a few cubes? You are not going to gain a whole bunch just from a max over bore. But to answer your question, If they are all that thick, then I guess ya could. But remember that limits the block, and if something happends you might have to start over. Kasey

Re: early 360 block thickness (sonic test) [Re: Moparnut426] #760645 07/29/10 10:01 AM 07/29/10 10:01 AM
Joined: Jan 2007 Posts: 3,695 nc E emarine01 master
emarine01 master E Joined: Jan 2007 Posts: 3,695 nc	We had several early blocks tested, they seem to be hit or miss, you need to check all cyls, one thin wall can set you way back, the most we have cut a 360 block has been .060 on a 73 block, I don't know on the tooling thing between 340s & 360s sharing the same walls

Re: early 360 block thickness (sonic test) [Re: emarine01] #760646 07/29/10 04:54 PM 07/29/10 04:54 PM
Joined: Mar 2010 Posts: 162 monticello,ms andy3965 OP member
andy3965 OP member Joined: Mar 2010 Posts: 162 monticello,ms	as stated in the original post i am only going .30 over. just wanted to know if i would be able to get two more rebuilds out of it. 4.06 & 4.10? or possibably 4.08? MOPAR BORN,MOPAR BRED,AND WHEN I DIE I'LL BE MOPAR DEAD!!!

Re: early 360 block thickness (sonic test) [Re: andy3965] #760647 07/29/10 06:09 PM 07/29/10 06:09 PM
Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again Moparnut426 I Live Here
Moparnut426 I Live Here Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again	ooops, Sorry speed read the post. Id say .030 would be fine. And from there, you can go .010 increments unless its really trashed. I know you can custom order diamond pistons in any size, and they arent much more than a set size as a comparison. My pistons were cuatom, and only like $40 bucks mor for the set. They opened my valve reliefs up for the 2.08 valves, and made them with the small chevy pinn size. Kasey

Re: early 360 block thickness (sonic test) [Re: andy3965] #760648 07/29/10 06:59 PM 07/29/10 06:59 PM
Joined: Nov 2004 Posts: 3,544 Syracuse,NY CompWedgeEngines master
CompWedgeEngines master Joined: Nov 2004 Posts: 3,544 Syracuse,NY	After three .030 rebuilds, which unless someone REALLY screws up, should never happen, you'd be at .231 thrust and .195 non thrust, which is very good. The problem as mentioned is, make sure ALL bores are sonic checked. You often get to the last cylinder and find its something stupid like .070 between cylinders.Check them all, if it maintains that kind of number, you have an exceptional block. RIP Monte Smith Your work is a reflection of yourself, autograph it with quality. WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.

Re: early 360 block thickness (sonic test) [Re: andy3965] #760649 07/29/10 07:29 PM 07/29/10 07:29 PM
Joined: Aug 2004 Posts: 293 Michigan C ccarson enthusiast
ccarson enthusiast C Joined: Aug 2004 Posts: 293 Michigan	I also have an early 1971 360 block, I dont have the inspection sheet in front of me, but if I recall, when we had it sonic checked the worst Thrust surface was .260" Yes I have heard the early 360 blocks were cast using the 340 cores. I wanted to bore mine .060" so with the 4.125" Stroke I would end up with a 426 but was talked out of it and we only went .030"

Re: early 360 block thickness (sonic test) [Re: ccarson] #760650 07/29/10 08:35 PM 07/29/10 08:35 PM
Joined: Mar 2010 Posts: 162 monticello,ms andy3965 OP member
andy3965 OP member Joined: Mar 2010 Posts: 162 monticello,ms	thanks for the info guys, i was just thinking about rebuilds using off the shelf sizes.this 408 i'm building is going in my '75 shortbox d100. i have a set of w2 econos with light port job(don't have flow numbers, they at the machine shop now getting flowed) and i bought a custon bullet solid lift cam from ryanj. gonna use a victor intake, flat top pistons,gonna stay in the 10.5 range on compression.ryan said my combo will be about 550-570hp and around 530 tq. should be a nice motor for my truck.going to be a street truck with the ocassional run down the strip Last edited by andy3965; 07/30/10 02:38 PM. MOPAR BORN,MOPAR BRED,AND WHEN I DIE I'LL BE MOPAR DEAD!!!

Re: early 360 block thickness (sonic test) [Re: andy3965] #760651 07/29/10 09:55 PM 07/29/10 09:55 PM
Joined: Dec 2008 Posts: 415 Peru cbarracuda mopar
cbarracuda mopar Joined: Dec 2008 Posts: 415 Peru	340 and 360 up to 1973 74 are made of a hi nickel alloy,the same material used in chryslers race blocks.Early 73 74 have more material in the cylinder bore and are heavier duty.Those early 360 are special case, they used 4 inches bore but the block was made with 340 water jacket core this means that these blocks can be bore to 340 size Last edited by cbarracuda; 07/29/10 09:58 PM.

Re: early 360 block thickness (sonic test) [Re: cbarracuda] #760652 07/29/10 10:05 PM 07/29/10 10:05 PM
Joined: Mar 2010 Posts: 162 monticello,ms andy3965 OP member
andy3965 OP member Joined: Mar 2010 Posts: 162 monticello,ms	thats some good info. that makes me feel real good about this block. its strong and thick,and i'm adding a hughes girdle. so this thing should have a strong bottom end. MOPAR BORN,MOPAR BRED,AND WHEN I DIE I'LL BE MOPAR DEAD!!!

Re: early 360 block thickness (sonic test) [Re: andy3965] #760653 07/30/10 12:55 AM 07/30/10 12:55 AM
Joined: Nov 2004 Posts: 3,518 pacific northwest S Stroker Scamp master
Stroker Scamp master S Joined: Nov 2004 Posts: 3,518 pacific northwest	that block is thick compared to mine, your fine with what you want to do, my block was in the 200's some spots lower, good perhaps, not, but its still together, 6112593-scampleap940x620.jpg (104 downloads) footbrake N/A SB 408 Scamp 10.10 @ 132 street/strip 73 Duster 340 street strip 12.79 @ 105

Re: early 360 block thickness (sonic test) [Re: Stroker Scamp] #760654 07/30/10 01:04 AM 07/30/10 01:04 AM
Joined: Aug 2007 Posts: 2,449 nc E earthmover top fuel
earthmover top fuel E Joined: Aug 2007 Posts: 2,449 nc	so my 340 thats 40 over should be fine if i sonic it...lol i want to build a (416) or what ever that comes out to be 422 i think not sure but 340 with 4.00 stroke and 40 over bore and flat tops and good rods rhs heads done to the max a good soild cam or roller should be 500/550 hp thanks mike

Re: early 360 block thickness (sonic test) [Re: earthmover] #760655 07/30/10 08:47 AM 07/30/10 08:47 AM
Joined: Mar 2006 Posts: 9,882 MI, usa dvw master
dvw master Joined: Mar 2006 Posts: 9,882 MI, usa	My 360 out of my 76 Volare sonic checked enough to go .060". Don't remeber the numbers but its been together since the early 90s. Still in my Challenger. Doug

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