Part number help • The Dodge Challenger Message Board

by **shatar4** » 24 Jun 2006 1:27

I am in the process of tearing down my 440 to get it degreased and checked for cracks but was wondering if anyone can tell me the part numbers on my pistons and rods. pistons have 3418231 with a pentstar on one side of the piston and 3418230 on the other side. The rods have a part number of 2951908. Thanks

by **dave-r** » 24 Jun 2006 8:46

The rod is a "six pack" rod although most 4bbl HP and HP2 440s came with them as well. make sure you use new very good quality rod bolts with these.

The piston is probably a stock piston. I don't have numbers for these myself. You don't say what year it is but all you have to do is measure it to see what size it is.

If it is the stock size and you tell me what year engine it is i can tell you the compression. But I would probably be wasting my time because you will be replacing these cast lumps of poo poo anyway won't you? Put them in the trash and forget about them.

by **shatar4** » 24 Jun 2006 20:06

The block has a 69 casting date but is a G440HP with a build date of 12-16. The bore size is 4.32. What is the stock bore size of a 440? There is no lip at the top of the bores so I don't think they need bored out anymore.

by **dave-r** » 25 Jun 2006 8:01

Mmm. So it was built in December 1969 but was fitted in a 1971 model?

Very strange. Normally the engine would be built just a couple of months at most before being fitted to a car. So this would normally be in a 1970 model. Unless if is a warrenty replacement engine?

Does it have the corrct VIN stamping on it? Replacement engines normally have a blank VIN pad.

I will assume this engine is built to 1970 spec so it will be 9.7:1 compression. The 1971 models had 10.3:1 advertised compression.

The bore size is completely stock at 4.32. Your choice to keep the stock heavy pistons or not.
Modern lighter pistons will improve the engine but you will have to get the crank etc re-ballanced. Also most replacements will be 30 thou oversize.

That all costs money of course but the factory didn't ballance them too well anyway so it will be smoother with a ballance and new pistons will add a little power and allow it to rev faster.

If it was mine I would fit new rings and leave it at that.

Note. With these six pack rods you need an external balance type crank damper unless you get it internally ballanced.

by **shatar4** » 25 Jun 2006 10:55

The block has a six pack balancer on it. I am hoping it has the six pack crank in it to but have'nt got that far as to pull it out. Do they have a part number on the crank so I can check that also?

by **dave-r** » 25 Jun 2006 17:20

It will have a forged crank. No need to worry even if it had been replaced with a cast crank. The cast crank did not come into use in the 440 until about 1974. But it will still take plenty of HP.

Easy way to tell the two apart is to look at the parting line running down it.

by **shatar4** » 25 Jun 2006 20:13

Thanks for the pics Dave-r. After checking, it does have the steel crank in it.

by **JackT** » 26 Jun 2006 1:02

"The block has a 69 casting date but is a G440HP with a build date of 12-16"

The engine's assembly date would have to be 12/16/1970 to have the "G" on the stamp pad and that would indicate that it was built to 1971 model year specs. I have been hunting for a 1971 engine for someone and have looked at two engines for him - both blocks were cast in 1969, had G stamped on the upper stamp pads and 1 in the series number stamped on the lower one by the pan, so it seems this is somewhat common.