I don't have my old MP Catalogs available. I think they made a couple different ones. 4.50 bore

What I know:
4 bolt main
4.38 Bore
Water Cooled
Cast in 2003

What I don't know:
Siamese?
Capable overbore?

Right now its an aluminum rod 540 built as a Truck Pull or Mud truck that ran alcohol.
I have to get it apart to determine cam and a few other things.

Thanks in advance.

Going by your specs and what's on the list, your block has to be P5007624. I bought an all new 540 shortblock from someone who had it built for truck pull. Thankfully, he saved the paperwork that came with the block.

Thanks. Im trying to find out more about the engine since it was built some time ago and the original owner is deceased.

I have contacted Indy and JE-

Are you going to pull a head? If so it will be easy to tell if it's a siamese bore block by poking a piece of wire in a casting core hole on the deck that is between 2 cylinders and see if is goes between them.

I think all the early blocks where the Mega blocks that didn't like to be bored much over 4.410
Maybe someone on here will know when the first World cast iron replacement blocks started entering the Mopar inventory
One of the local racers had several of those early Mopar Mega blocks that had cracked at 4.500 but lived at 4.410 to 4.440 bore sizes
I would have it sonic tested before boring it any bigger

I must have lucked out on this early ('01) block. The builder stated in the notes that it's good up to a 4.56 bore

Probably need to verify that because cab is correct. Those early ones were kinda thin.

According to the sheet above, there are several blocks with a max overbore of 4.31". Must be referring to those.

Verifying the max bore would be mandatory anyway if i were to have it bored for a 572

My mega block was one of the last ones that
Mopar built.. even at 4.500 bore it still had
.200 wall thickness... that was with 64 readings
per bore
EDIT
this was a 4.19 siamese block that I was told to
get vs the 4.5 bore because of the bore quality
and would need to be redone

I have the Heads off. So ill check the water jackets.

Heads are 572-13 2.35 Valve O-ringed heads and block.
Jesel Rocker System. BIG offfset on Roller Lifters

JE said not much info on the job. They did give the bore at 4.38 and a 1.301 Compression Distance. .990 pin.
Pistons have as much Dome as Valve relief.


I will have to CC a cylinder with a piston in the hole to figure out compression. May have to change pistons to Run Gas or E85.

There are aluminum rods but with a mirror I cannot find a manufacturer on Rods or Crank.

JP Performance Chain
Cam Motion R2826 2862-11
Got the Card Today and its like 790/745 w 1.7, 281/290 @.050 111 lobe separation.

Fortunately all is super clean and nothing broken. Prob need to start another post to discuss options with these parts once I figure out compression. I 'd like to use it in 72 Demon that always ran Race Gas.

[quote=jughed]Going by your specs and what's on the list, your block has to be P5007624. I bought an all new 540 shortblock from someone who had it built for truck pull. Thankfully, he saved the paperwork that came with the block.

If you look at the description under the part numbers Jughead posted it says the siamese blocks have Mopar in large letters cast in the block. Both the P5007624 and P5007625 are the same block but one is bored to 4.19 and the other out to the max bore of 4.50.
I have a 2468330 M hemi block that is a 4.31 max bore water jacket block and it doesn't have the Mopar cast above the numbers.

Hope this helps, Mike

The Block

siamese 4.50