351/702 pistons option
 

OK, here is a a crazy *** idea, it might work, and it might not:pullinghairout:
The international v-537/605 engine has a 4.625 std piston with a 1.313 in pin. (???) If I have read that correctly, at my age that is always questionable, is it possible to use this piston in the 351/702. What I don't know is the compression height. If it is within a few thousands the top of the piston can be reduced. The piston can be re-bushed to fit 1.25 GMC.
OK, let's shake the bushes and see who had gone this route and found a dead end.:banghead:

Edit time , aw rats, compression distance-2.31"
wrist pin-1.31
approximately .5" from the surface to the top ring and .200 dome
3 rings

Maybe a little long rod ???!!!

Re: 351/702 pistons option
 

The bore is very close to the 351's 4.56 inch bore but piston pin height may be the issue If the piston pin height is higher on the International piston then you can have the crankshaft stroked accordingly, good chances the piston pin heights are different. You may be better off with a custom set of pistons or contact ThunderV12.com and see what they have to offer.

Re: 351/702 pistons option
 

What would it cost to resleave the block and stay with stock pistons? I think thunder v12 wants 4 grand for a set of pistons

Re: 351/702 pistons option
 

I was just looking for other piston options. The compression height for the V-537 IHC is to short. The 351 is 2.562 in and the v-537 IHC is 2.31 in.

Re: 351/702 pistons option
 

Have you tried Arias Pistons for a set of custom pistons?

Re: 351/702 pistons option
 

I am forwarding the email recieve from Arias, sounds like if we placed an order of at least 24 pistons we could get jobber pricing. Hi Bob-
Thanks for contacting ARIAS. Yes, we have made custom pistons for the 305 and 351 GMC V6. We have the capability to make the 702 V12 pistons also. There is a price difference between the two engines due to the bore diameter (the V6 is lower cost). Here's what I can offer on orders of 12 (for orders of 24 and up I can offer Jobber pricing).

Pistons: $130.09 each (flat top)
Pin fit: $3.82 each
Internal milling for lightening: $29.61 each
Pins, STD duty: $19.51 each
Pin locks: $1.84 each cylinder
Rings: $32-67.00 each cylinder (depends on bore size)

Custom piston options:
Coating, Moly skirt: $21.41 each

Let me know what you need!


Thank you,

Nick Arias III
www.ariaspistons.com
310-532-9737 ext. 37
310-516-8203 fax

Re: 351/702 pistons option
 

Arias has made my custom pistons for many (20-30)years. Great people, accurately mfg'd components and they'll accept my poor drawings and specs desired. They'll contact you with suggested design revisions based on their years of experience. Excellent company. Nick, Jr ran 302s yrs ago. Good times.

Re: 351/702 pistons option
 

I will add that any replacement piston is very apt to weigh much differently than the original. Arias will probably spec 2018 alloy for bore sizes of our V6 and V12s. Probably much lighter. A V6 is very sensitive to engine balance, so I strongly suggest a total eng rebalance. Discuss reciprocating % factor w/ the balance people. Include the pressure plate asmy and DISC to have a smooth, sweet running, long lasting unit.

Re: 351/702 pistons option
 

One thing also to consider. Arias Piston keep's the 1.24 in piston pins in stock.

Re: 351/702 pistons option
 

Posted a thread on the Marketplace/For Sale site awhile ago - anyway still have (2) broken sets of 351/702 .030 oversize pistons - (5) Zollner Z-4653 clear-o-matic and a set of 6 unmarked (1) has a deeper dish and (2) are marked bad/no good by my machine shop. I ended up buying 3 sets of old stock pistons before I ended up with 6 I could use. Have (12) used rods for sell too. If interested - email me. Thanks, Cliff