Wow how far can you bore a 340 before you go to far

[MILO]

1970 Plymouth Duster For Sale | 331-SAN

Offered from Gateway Classic Cars (#331-SAN), this Beige 1970 Plymouth Duster powered by a 340 ci bored to a 418 V8 engine with a 727 Torqueflight Automatic transmission. We have 3728 Classics For Sale in our 21 Indoor Showrooms Nationwide.

www.gatewayclassiccars.com

 

[66fs]

Never bore more than it takes to get round, straight bores. That motor has a stroker crank to get that big displacement.

 

[Jadaharabi]

With the right block and crank you can build a 440ci 340.

 

[rumblefish360]

Here is your answer!

As far as a sonic check says the walls are thick and your machinist will know (or freaking better!) how far is to far.

I have had 340’s cylinders so thin the machinist didn’t want to touch the virgin block saying it was a paper weight as deliver d from the factory.

I also have a OEM 340 where my machinist said he would take it an.100 over, no sweat, no problem!

THE BOTTOM LINE IS SONIC CHECK BLOCK BEFORE YOU DO ANYTHING!

Now what that advertisement fails to say is that the block has been BORED & STROKED to its displacement!

 

[RustyRatRod]

That's probably a 4.070 or 4.080 bore. That's only .030" or .040" from stock, respectively.