Hello, I'm new on this forum. Could anyone suggest where to buy online Original GM Pistons for a 1998 Chevy Blazer? Could non-original be a reliable alternative? Any suggestion is most welcome. thanks in advance.

 

Genuine GM pistons in standard bore (88894280), no rings. $600/set
#23 in:
https://www.gmpartsdirect.com/v-1998...engine--engine

Non-original aftermarket pistons are fine as long as pin height is correct and they weigh the same. These should do fine (0.030 over). I assume you are planning to bore the cylinders oversize to give a new finish to them. Summit Racing will ship to Italy. They also have the rings and tech support to answer any questions that you might have by phone, internet chat, or text. Summit is a large parts company here in the US.

https://www.summitracing.com/parts/S...de/w/year/1998

Good luck

 

Hello LesMyer and thanks for your comments.

I confirm my mechanic's plan is to bore the cylinders oversize to give a new finish, however he is very skeptical on using non-original parts. To my knowledge the 4.3 L (262 cu in) V6 has a 4 in × 3.48 in (101.6 mm × 88.4 mm) bore and stroke. Any idea if GM ever made oversize Pistons? I couldn't find them on gmpartsdirect.com so I guess the only alternative is the aftermarket option. Do you think that those suggested in your thread could meet or exceed the original GM quality?


I also found these two at Summitracing:
Any idea if the original GM are made by AcDelco?This seems like the original STD version
ACDelco Pistons 88894280 PISTON ASM,(W/ PIN)(STD)
https://www.summitracing.com/parts/ado-88894280

And this seems to me like the Oversized version that could fit the bored cylinders.

ACDelco Pistons 88894282 PISTON ASM,(W/ PIN)(0.50 MM O/S)
https://www.summitracing.com/parts/ado-88894282

Thank you in advance for your help.

 

Yes, I found the 88894282 pistons at Summit are GM pistons and seem to be approximately 0.020 oversize (0.5mm). But with Auto Workers Strike I think you will have a lot of trouble finding them if they are not made already and in-stock at a non-GM company that re-sells them.

Most of the GM factory parts like this that Summit sells, they drop-ship directly to customer from General Motors. I have ordered GM parts from them this way before. You may or may not have trouble getting shipment to Europe on a drop-shipped order.

To me, the cost of GM pistons do not warrant the extreme high price. I used the Sealed Power/Speed Pro pistons in my own Blazer (ones that I linked to in post #2). In my opinion they are same quality as GM and a LOT less expensive. There is little market for $600 piston sets for old 1998 Blazers and this makes the GM ones rare and difficult to find.

I would use the Sealed Power H640DCP pistons without worry.

AC/Delco supplies the replacement version of GM parts and typically has a different part number. In this case 12571703.

I believe another option for shipping to Europe is Rock Auto. They only list parts that are in stock that they can ship right away. Almost always the very best price and you can find 5% discount codes. Maybe you will want to check them out.

 

Thank you LesMyer for your precious comments. I'll check with Summit what they have available. I might end ordering what you suggested in your previous thread if they have them in stock and my mechanic agrees to go ahead with the aftermarket parts.

 

Did you also order a Ring Kit when you ordered the Speed-Pro Hypereutecnic Piston H640DCP 30 set?

 

Yes, I used Sealed Power E-229K30 rings. They are Moly rings for 5/64" x 5/64" x 3/16" grooves in the H640DCP 30 pistons. These H640DCP pistons have a compression height (of 1.540) which allows for decking of the cylinder block head surface 0.020 while maintaining exactly the same piston height as original. These are called "rebuilder pistons" and are very popular because they also fit 350 Chevy V8. If you think that you need the original compression height (of 1.560") pistons then you will need to search for them.

https://www.summitracing.com/parts/slp-h640dcp30
https://www.summitracing.com/parts/s...azer/year/2001

You might want to order some new head bolts since they may be difficult to get in Europe. Their final tightening value is an angle tightening measurement of 90 degrees (measuring bolt stretch). These bolts come with the thread sealer already printed on. Of course be sure to run a tap type thread cleaner through the head bolt holes in the block (clean and dry threads except for sealer). You will need two of these sets of bolts - once for each head.
https://www.summitracing.com/parts/f...azer/year/2001

Of big concern is the intake manifold on these engines. Lots of trouble early on with intake manifold gasket leaking coolant internally and ruined engine bearings. These bolts are very sensitive to how they are torqued and if too tight (as reported by GM) can stretch engine block middle webbing and ruin main bearings. Too loose and they will leak. I like to check torque on them 1 more time after sitting overnight. You can make sure original bolts are perfectly clean and dry (as well as the receiving threads) and then put on liquid teflon thread sealer. Or you can order new bolts with the sealer already printed on.
https://www.summitracing.com/parts/f...azer/year/1998

Felpro has developed a rubber bonded on metal type intake gasket (PermaDry Plus) that is much better than the plastic ones that were originally (and still are typically) used - but they are more expensive and do not come in big gasket sets. Also they are on backorder at Summit. Maybe you have a Felpro distributor in Italy that can get them?
https://www.summitracing.com/parts/f...azer/year/1998

 

Rock Auto 5% Discount Code:Code : 248037325215709625
Expires 11/24/23

 

Thanks a lot for the exhaustive instructions!

Rockauto has in stock the SEALED POWER ref no. H645DCP (not H640DCP 30 that you indicated on Summitracing) but the specifications seem to be the same to me, apart from the Compression Size (in.):
1.540 for H640DCP 30 (Summitracing) and Compression Size 1.548 H645DCP (Rockauto) . Does it make any diference?

https://www.rockauto.com/en/moreinfo...MMfgve8w%3D%3D

Furthermore they have all you suggest in stock:


https://www.rockauto.com/en/moreinfo...MMfgve8w%3D%3D

https://www.rockauto.com/en/moreinfo...MMfgve8w%3D%3D

https://www.rockauto.com/en/moreinfo...MMfgve8w%3D%3D

https://www.rockauto.com/en/moreinfo...MMfgve8w%3D%3D

I'll place the order using the Rock Auto 5% Discount.
If you suggest SEALED POWER ref no.H640DCP 30 I could easily place two separate orders (Summitracing + Rockauto).

 

The H645DCP 30 pistons are for the 1985-1991 VinZ or VinN or VinB 4.3 engines, according to the Summit "Check the Fit" feature. Although the piston dimensions are fine, I am quite sure they weigh differently. The older engines were balanced differently, especially the years before the balance shaft.

You should have a vin W engine (8th digit in VIN of vehicle) with balance shaft. I still recommend the H640DCP 30 which I can see are available on Rock Auto. At least they are available for buyers in the USA. Please recheck (don't include the "30" when searching).

Only bad thing about Rock Auto is that often the shipments on a multiple parts order are split up, and they ship from multiple locations. It works differently for them. Multiple shipments, if required might be costly and ultimately make Summit the better choice for International shipment. I would check total cost from both Summit and Rock Auto before making a final decision. I have no experience in using Rock Auto to ship Internationally. But they almost always are the best price on a single part.

Good luck!