361 Block

[Chambo]

Hi all, I have a 66 Charger here is Aus with the 361.  Im looking at a supposedly a 383 block but after investigating the block numbers it's another 361 and not a 383.  The hitch is that the bore measures 4.320 which is 440!!! Can anyone shed some light on how a 361 can be taken out to 440???
Regards,  Glenn

[Nacho-RT74]

if it takes up to 4.342 ( which is standard 400 )  you can get a 440 crank and become it on a 444 which is the same than a 440 bored 0.020" ( 0.022 actually, but who cares those cents on this math )... that would be a stroker... RB block stroke into B block deck height with the bigger stock size pistons bore available from Chrysler. Pistons available for it are Keith Black KB215 ( as told, standard 400 ). Crank would need to be cut to fit ( mains and counterweights ).

But... dunno about the wall thicknes of 361 to hold the 400 bore

[John_Kunkel]

The physical overbore limit is when you bore through to water. The practical overbore limit is when the cylinder walls become precariously  thin...only an ultrasound test can determine that.

Sure, a 361 can be "taken out" to 4.320" (.195" over) but would you want to run it? I wouldn't.

[c00nhunterjoe]

The physical overbore limit is when you bore through to water. The practical overbore limit is when the cylinder walls become precariously  thin...only an ultrasound test can determine that.

Sure, a 361 can be "taken out" to 4.320" (.195" over) but would you want to run it? I wouldn't.

Agreed. In my experience,  60 over is safe. Past that requires sleeves. Ive seen 90 on stock sleeves buts thats crazy thin and unreliable from what i have seen. Personally never gone over 100 on a stock sleeve. Wonder if some of our resident engine masters will chime in. Are you sure you measured that bore correctly?

[Chambo]

Yes definitely measured correct, it's at the engine rebuilders who measured it. I know the 361 is a different block to the 383 and thought it could'nt be bored to out to 383 let a lone 440. If it has been taken out that far I won't be buying it.

[Nacho-RT74]

The deal is even if you have the 440 bore you won’t find a 440 piston out of the shelf to fit on a B stroke unless custom made. Dunno if you could cut a Low compression 440 piston and cut it safe to fit into the B block ? Would need to cut it around 0.055-0.065” per what I can read around.