383 or 400 ?

[RustyRatRod]

Looking at the various offerings - you have to be careful on which 440 pistons you want to use. A stock 440 piston is shorter than a stock 400 piston by about .065". That would make the 400 even lower compression than a factory 400 piston would. Using the hyper KB237 - those are much taller, and if you used that with the factory 400 crank and rod it would stick out of the deck over .100". The L2276 TRW will stick up about .025" give or take based on a blueprint deck height. The good news is they're usually taller than blueprint.

So - while it might work I'd suggest you do your homework. It's not like any 440 piston will work well.

HECK yeah. What he said. ^^^^^^^

IMHO, I think folks make too much ado about the 400's compression. Yeah, it's dismal, but you still have 400 kyoobs. It's GONNA make power as long as you do some good head work and put a good induction and exhaust on it. and look at what you'll have. A snappy engine that'll run all day on 87 and never say one word.

 

[69conv]

Courtesy of Heyoldguy

1/2 stroke=1.69"
rod length=6.358"
CH=1.926"
Total=9.974"

400=9.98"

When installed my pistons were .005 in the hole.

 

[451Cuda]

HECK yeah. What he said. ^^^^^^^

IMHO, I think folks make too much ado about the 400's compression. Yeah, it's dismal, but you still have 400 kyoobs. It's GONNA make power as long as you do some good head work and put a good induction and exhaust on it. and look at what you'll have. A snappy engine that'll run all day on 87 and never say one word.

The problem is when people put a big cam in and wonder why it has soggy low end torque. If you stick with muscle and rv type cams it runs just fine.

 

[dukeboy440]

The 400 probly has low compression which can be fixed by boring slightly to take 440 pistons but has the hardened seats. Either one will fly!

You realize that the 400 has a bigger bore than the 440 right? :wack:

 

[YY1]

KB 240, but $470.

My running carb to oil pan 73 400 with trans was $300.

 

[RustyRatRod]

The problem is when people put a big cam in and wonder why it has soggy low end torque. If you stick with muscle and rv type cams it runs just fine.

Puzackly. The Road Runner cam to me, is one of the best all around street cams money can buy for an everyday driver big block. They just WORK. You're right. People put big intakes, bug carbs and big cams on low compression engines expecting them to run good. But they can run good if you are smart with your parts choices. Just look at that low compression 440 build Jim Laroy did. That's proof to me that power can be made with low compression. It's all in the heads, as Jim says all the time.

 

[bOb shingler]

one of the things you might want to look at is the compression height of the pistons and pick one that moves the top of the piston closer to the deck. measure how far down in the hole the stock on is and pick accordingly.