stroker kit question

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B5BEE

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So I picked up a Mopar performance stroker kit locally for pretty cheap for a 340 as it was advertised. After checking out the pistons to my stock 340 bore they measure 4.030 and my block is a stock 4.040. The part # I have is mopar performance P4876972 for the pistons. Rods P5249746 and the crank is p4120312.

My question is can I run this smaller piston or is it too loose? Or is it strictly for a 360. New to small blocks. Thanks.

I've searched the web and cannot find anyone with these part #s.
 
Sounds like this is a combination for a Mopar race block which came rough bored to 3.91 or if you are lucky a 318 with thick cylinder walls if if would sonic check to that thickness. I found the following on another Mopar web site.

"It is an 'A' engine crankshaft, surface hardened, forged 1053 steel small block crank,featuring radiused fillets at main and rod journals, eight bolt flanges,straightness checked (318 mains). This is Part # P4120312. This is a 3.45" stroke."

This would give you ~ 355 cubes.

Here is a link also to another article with the crank part numbers referenced.

http://books.google.com/books?id=S7...ed=0CBkQ6AEwATge#v=onepage&q=p4120312&f=false
 
Rocket said:
Sounds like this is a combination for a Mopar race block which came rough bored to 3.91 or if you are lucky a 318 with thick cylinder walls if if would sonic check to that thickness. I found the following on another Mopar web site.

"It is an 'A' engine crankshaft, surface hardened, forged 1053 steel small block crank,featuring radiused fillets at main and rod journals, eight bolt flanges,straightness checked (318 mains). This is Part # P4120312. This is a 3.45" stroke."

This would give you ~ 355 cubes.

Here is a link also to another article with the crank part numbers referenced.

http://books.google.com/books?id=S7...ed=0CBkQ6AEwATge#v=onepage&q=p4120312&f=false
Click to expand...


Thanks, he did say he had a mopar performance race block for sale also. over my budget though.
 
If you measure the rods and piston compression height carefully you may be able to use in a 360. You could then sell the crank and buy the appropriate 360 crank.

You have a few options but will need to switch a part or 2 depending on what the measurements tell you.
 
B5BEE said:
So I picked up a Mopar performance stroker kit locally for pretty cheap for a 340 as it was advertised. After checking out the pistons to my stock 340 bore they measure 4.020 and my block is a stock 4.040. The part # I have is mopar performance P4876972 for the pistons. Rods P5249746 and the crank is p4120312.

My question is can I run this smaller piston or is it too loose? Or is it strictly for a 360. New to small blocks. Thanks.

I've searched the web and cannot find anyone with these part #s.
Click to expand...

You can not use the pistons. To loose. The slugs are for a .020 overbored 360.
 
B5BEE said:
So I picked up a Mopar performance stroker kit locally for pretty cheap for a 340 as it was advertised. After checking out the pistons to my stock 340 bore they measure 4.020 and my block is a stock 4.040. The part # I have is mopar performance P4876972 for the pistons. Rods P5249746 and the crank is p4120312.

My question is can I run this smaller piston or is it too loose? Or is it strictly for a 360. New to small blocks. Thanks.

I've searched the web and cannot find anyone with these part #s.
Click to expand...

You can not use the pistons. To loose. The slugs are for a .020 overbored 360.
I did not look up the crank specs.
 
Part # P4120312. This is a 3.45" stroke for 340 mains.

Rods P5249746 is a heavy duty 4340 steel rod.....
 
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