340 pistons in a 360?

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dibbons

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A local Mopar buddy here has a 71 Cuda, 69 Road Runner, 69 Dodge Charger. He also has a 440 with a gear drive on an engine stand and a Dana 60 on his shop floor that that he says both came from a Dick Landy vehicle. He says he can use standard 340 dome pistons in an overbored 360, is that true? Thank you.
 
340's and 360's have different compression heights... Different stroke, same length rod, the difference is in the piston... I don't think that they will work properly....
 
I think standard 340 pistons can be installed in a 360 IF the 360 is .040 over AND a small amount of the pistons is milled off the top (not sure on the amount). I've never attempted, nor would I. However, I've talked with folks that claim they have done it.
 
both engines share the same deck height...340 high compression piston has a compression height of 1.84...360 piston is 1.67.....you will have about .170 of piston sticking out of the deck...hitting the head....plus the skirt on the 340 piston must be machined to clear the 360 crank......

this was used with low compression pistons back in the early 70s went there were not many choices of 360 pistons...today there are many more choices of 360 pistons vs the 340....plus the low compression 340 piston still required the top of piston cut plus the skirt machining to clear the crank counterbalances.....a guy name Tom Hoover did a machine article on it...

the low compression 340 piston was used and has a compression height of 1.74..so the cut is not as much..but with the machining cost of cutting the piston and the clearing the skirt...buy the correct piston for the 360...
 
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both engines share the same deck height...340 high compression piston has a compression height of 1.84...360 piston is 1.67.....you will have about .170 of piston sticking out of the deck...hitting the head....plus the skirt on the 340 piston must be machined to clear the 360 crank......

this was used with low compression pistons back in the early 70s went there were not many choices of 360 pistons...today there are many more choices of 360 pistons vs the 340....plus the low compression 340 piston still required the top of piston cut plus the skirt machining to clear the crank counterbalances.....a guy name Tom Hoover did a machine article on it...
Yes, this! Been a long time since I visited that thought, but this is how and why it was done.
 
Basically the answer is no though Tony did describe the old build above. It would be stupid to do such a thing now considering all the piston choices out there today and there low cost.

The reverse is more plausible to do. A oversized 360 slug in a 340. This is a normal venue to choose when installing a 360 crank into a 340.
 
The 340 pistons are also very heavy . He would better off buying a good set of pistons than spending it on mallory.
 
I run a 70 Caged Dart 360 with 340 cast pistons cut to zero deck,282S XE , 67cc XO Heads Ported twisting a 4:30 gear.
ET 11:81 in the heat. Its been doing it for years.
 
Mine was built in the late 80's . Not many options then .
Today would be a different deal .
It's still kickin it today though.
 
I run a 70 Caged Dart 360 with 340 cast pistons cut to zero deck,282S XE , 67cc XO Heads Ported twisting a 4:30 gear.
ET 11:81 in the heat. Its been doing it for years.
That's a cool combo,considering a friend built a 360 with stock 360 forged replacement pistons,he milled WELL over .100" off the decks.Ran hard,eventually the block succumbed (Too Many 250 N20 hits...)
 
Mine was built in the late 80's . Not many options then .
Today would be a different deal .
It's still kickin it today though.
There ya go... things are sooo different now for parts than when I started in the early 70's. Mostly better choices.

The one recent example of cutting some pistons that I ran across recently was for cutting some early 50's Ford cast pistons down for 273 use. Doing a 273 now is like doing a lot of engines 30-40 years ago.
 
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