Seal power numbers question for duke & joe l

[Bob W.]

I'am starting to buy parts for my 58 283. The block is 40 over and the crank is cut 10. Looking at seal power pistons,rings and bearing sets.These are the numbers I came up with I just want to be sure before I order.

pistons-235np40
rings-e245x40
main bearing set-138m10
rod bearing set-c87065ch


THANKS BOB

[Joe L.]

Re: Seal power numbers question for duke & joe l

I'am starting to buy parts for my 58 283. The block is 40 over and the crank is cut 10. Looking at seal power pistons,rings and bearing sets.These are the numbers I came up with I just want to be sure before I order.

pistons-235np40
rings-e245x40
main bearing set-138m10
rod bearing set-c87065ch


THANKS BOB

Bob------


Well, it's like this:

pistons---235NP40-----these are the correct, +.040", Sealed Power, standard cast pistons for your application. They are equivalent to the original pistons. They will work fine for you.

rings----E245X40---these are the correct, +.040", Sealed Power, standard pistons rings for your application. I would recommend the Sealed Power E245K40 piston rings. These are a premium, moly top ring set.

connecting rod bearings----138M10----these are the Speed Pro con rod bearings for your application. Both Speed Pro and Sealed Power are Federal-Mogul brands. However, Speed-Pro tends to be the "high performance" line. These bearings will work well for you. However, if it were me and I was wanting a completely stock type rebuild, I think I'd use the Sealed Power line bearings. These would be 8-2020CP10.

main bearings----C87065CH----just like the above, these are the Speed-Pro main bearings for your application. They will work fine for you. However, once again, for a completely stock type rebuild I think I'd use the Sealed Power line main bearings. These would be 994M10. Either the Sealed Power or Speed-Pro bearings should work fine, though.

[Bob W.]

Re: Seal power numbers question for duke & joe l

Joe Thanks for the reply. What would we do without you THE NUMBER MAN !!!!!!!

Bob

[Larry S.]

Re: Seal power numbers question for duke & joe l

Can not find 396/425HP pistons, anyone have source to get these? I see 396 pistons for 325,375HP but none rated for the 425HP L78.Need forged, closed chamber pistons.060 over.
I want a 11:1`to 11.5:1 compression ratio.

Thanks
longhornlarry

[Duke W.]

Re: Seal power numbers question for duke & joe l

I'am starting to buy parts for my 58 283. The block is 40 over and the crank is cut 10. Looking at seal power pistons,rings and bearing sets.These are the numbers I came up with I just want to be sure before I order. pistons-235np40 rings-e245x40 main bearing set-138m10 rod bearing set-c87065ch THANKS BOB

I'm not sure if those pistons are good for more than about 8.0-8.5 compression. Higher compression will yield better performance and fuel consumption, but you didn't state the configuration. I'd also recommend you look at the Keith Black line. I also recommend you spend $250 on a set of Eagle SIR5700 rods. The originals are weak and prone to fatigue failure. Lots of other things you should be looking at, but you've provided too little information on what you have and what you want to do.

[Joe L.]

Re: Seal power numbers question for duke & joe l

Can not find 396/425HP pistons, anyone have source to get these? I see 396 pistons for 325,375HP but none rated for the 425HP L78.Need forged, closed chamber pistons.060 over.
I want a 11:1`to 11.5:1 compression ratio.

Thanks
longhornlarry

Larry------


Pistons for the 1965 Corvette L-78 and 1966-E69 Chevelle L-78 were the same----GM #3878231. I don't know of an aftermarket source for these exact pistons but there may be one.