Yes, you are right, H640DCP they are available on Rockauto:
https://www.rockauto.com/en/moreinfo...oice=2-30O-0-1

I experienced Rock Auto many times in the past for shipments to Italy and they always had the best price on parts although as you wrote it happens on multiple parts order that they split up and ship from multiple locations. I'll check the total cost from both before ordering.

Thanks for your support.

 

If you have internal engine questions, Les is the man.

George

 

Thanks, George

 

You are welcome. If you have any more things to discuss please put them in this same thread. That way the forum will automatically send me email.

 

P.s. I see Rock Auto only has 3 left now. Maybe you already bought 6 of those, but if not you could go to 0.040 over. If you do that be sure to change the rings package too.

 

Hello Les, my mechanic has just called me and found that the pistons currently on my Blazer are marked 0.040 oversize. This makes sense as I bought the engine remanufactured from Rockauto in 2020 https://www.rockauto.com/en/moreinfo...&pt=5240&jsn=1

That said, the cylinders must be bored oversize of a further 0.040, up to a 0.080 in. oversized bore if compared to the standard bore (4.00 in.)
In other words the final bore would be 4.080 inches.

Going back to where we left the pistons H640DCP 30 that you recommended are oversized 0.030 in. only if compared to the standard bore and from what I see Sealed Power does not make pistons that are more than 0.060 oversize.

Any suggestion on pistons that would fit a 4.080 in.bore?

Thanks for your help.

 

0.060 is probably largest advisable overbore. Cylinder walls can get too thin. Also block should be sonic checked when going to 0.060 over. I would think that 0.060 bore would clean up cylinders unless they are absolutely horrible. Best wishes.

 

Hi Les, I double checked, but being a reman engine it already has 0.040 oversized pistons and the mechanic says that a 0.060 oversized piston is not enought and to solve the problem the cylinder needs to be bored up to 0.080 for clean up. Unfortunately I can't find an engine in good conditions here in Italy so I don't see a reasonable solution at this stage. Any suggestion is most welcome. thank you.

 

Silvolite 3445 and 3445C are the only ones I can find for a 4.3 that come in 0.080 over. Can't guarantee they weigh the same as they are for 1995 and earlier. Summit has them.

 

Summit says that Silvolite p/n 3445.80 are compatible with the 4.3v6 Blazer up to-2004 model year. I'm now witing from them the part number for a suitable Ring Set and Connecting Rod Bushings.