Is this true

-
1973dusterkid

1973dusterkid

Watch This
Joined
Jul 17, 2011
Messages
2,270
Reaction score
68
Location
Buford Georgia
I was seating in my car on brake from work and a guy pulled up beside me. He said he liked my car. The he said he had an original duel snorkel hood scoop that he would sell me. I got his number and said when I got the money I might call and buy it. We were talking and he said this.

I think he said it was the 71 or 72 360s that had a larger cylinder wall and could be bored out more he said you could bore them out to around 100 over is there any truth in this.
 
the rumor is 71 360s can be bored 100 over. It was in a magazine so it must be true.LOL
 
The early 70's 360 had a little more meat then the later ones. I don't know about .100 over though.
 
I wouldn't go .100 over on a 360 even if it sonic checked. Not to mention pistons would probably be a issue.
 
I know a dirt burner that has bored a few of them .100 up to 73 blocks never had any issues. He said to be sure and run a front engine plate to keep cylinder walls from distorting.
 
1970 La said:
I know a dirt burner that has bored a few of them .100 up to 73 blocks never had any issues. He said to be sure and run a front engine plate to keep cylinder walls from distorting.
Click to expand...

if I bored it any its would be .30 over but just wondring
 
We've sonic tested several 70-73 date coded 360s and all of them measure about twice as thick as the later 70s engines. Hensley Motorsports sells 408 strokers based on .090" over 318 blocks so obviously, it can be done. We have a Dakota Ultrasonics tester that cost about 2500 bucks and it's accurate. So far the rumor seems to be holding up.
 
StrokerScamp said:
We've sonic tested several 70-73 date coded 360s and all of them measure about twice as thick as the later 70s engines. Hensley Motorsports sells 408 strokers based on .090" over 318 blocks so obviously, it can be done. We have a Dakota Ultrasonics tester that cost about 2500 bucks and it's accurate. So far the rumor sees to be holding up.
Click to expand...

Seems like a real stretch to me. Would you do one for yourself? Just curious, and i value your opinion.
 
most of theese motors are race only but hell yeah! plenty of guys at local track running .90 and .100 over mopars. and winning races! thats all i need for proof.
 
Some say that the early 360 block walls were cast the same as a 340. The 340 was .040" larger bore to start with, and many will bore a 340 .060" over. If the walls are the same casting, then a 4.100" bore would be the same in either a .060" 340 or a .100" 360.

I would have one sonic tested before wasting your money, though. Even if it's true, core shift happens, and you could build an engine that is weak, ad likes to overheat.

And as far as finding pistons goes, when playing with a stoker crank, it's very easy.
 
I don't bore mine out any more than necessary. Rock hard and rigid makes more power (less blowby) than the few extra cubes you get.

In my opinion.
 
OldmanRick said:
Seems like a real stretch to me. Would you do one for yourself? Just curious, and i value your opinion.
Click to expand...

Real quick like. Long as it has at least .175" on the thrust side, real quick. Most of these we've tested will have more than that AFTER going .100 over. But I'm not saying all of them are like that......but we have yet to find an early one that's as thin as the later ones. Call Hensley. They'll talk to you about it.
 
damnimcooltom said:
Some say that the early 360 block walls were cast the same as a 340. The 340 was .040" larger bore to start with, and many will bore a 340 .060" over. If the walls are the same casting, then a 4.100" bore would be the same in either a .060" 340 or a .100" 360.

I would have one sonic tested before wasting your money, though. Even if it's true, core shift happens, and you could build an engine that is weak, ad likes to overheat.

And as far as finding pistons goes, when playing with a stoker crank, it's very easy.
Click to expand...

EXACTLY. We're just gettin lucky. LOL Sonic test or you'll be sorry.
 
jos51700 said:
I don't bore mine out any more than necessary. Rock hard and rigid makes more power (less blowby) than the few extra cubes you get.

In my opinion.
Click to expand...

100% agree. What we're doing is planning on using one or two early 360s that are already .060 over to begin with. Stroking by FAR beats out boring to get cubes. You bees right on the money.
 
StrokerScamp said:
Real quick like. Long as it has at least .175" on the thrust side, real quick. Most of these we've tested will have more than that AFTER going .100 over. But I'm not saying all of them are like that......but we have yet to find an early one that's as thin as the later ones. Call Hensley. They'll talk to you about it.
Click to expand...

Good to know, Thanks SS. I'm not thinking about going that far, but if i find a early block that's .040 or so at least i know there's still some life left in it.
 
OldmanRick said:
Good to know, Thanks SS. I'm not thinking about going that far, but if i find a early block that's .040 or so at least i know there's still some life left in it.
Click to expand...

Certainly worth checking out anyway. I aint sayin they're ALL like that, but the ones we've tested are.....so far.
 
I was told the 70/74 360 blocks were cast with the 340 water jackets, not sure how true it is though.I guess it would make sence.
 
You have to sonic test them. The fact they used the 340 cores is right, but the few I've tested ('71 cast 360s) had too much core shift so the bore was thicker, but the meat was in the wrong places to (by my definition) safely allow for larger overbores than .040. It also depends on what your expectations for the engine are vs what the minimum thickness is. I also think by the '73 casting dates they had thier own cores and were not using the 340's. Remember the 340 was killed by corporate decision well before production stopped so they had already tooled up for 360-specific production.
 
No kiddin, cause I've seen 360 blocks with 1970 date codes, so they were already out and about even then.

moper said:
You have to sonic test them. The fact they used the 340 cores is right, but the few I've tested ('71 cast 360s) had too much core shift so the bore was thicker, but the meat was in the wrong places to (by my definition) safely allow for larger overbores than .040. It also depends on what your expectations for the engine are vs what the minimum thickness is. I also think by the '73 casting dates they had thier own cores and were not using the 340's. Remember the 340 was killed by corporate decision well before production stopped so they had already tooled up for 360-specific production.
Click to expand...
 
You must log in or register to reply here.
-

Back
Top