'91 9C1 rebuild.....

So I call Summit today to order a master rebuild kit with forged pistons and stage II summit rods and they tell me they don't have a kit for my boat. They mentioned something about a .167" shallow oil groove. Why can't I order any pistons for this thing!?!?

'91 B-body LO5 5.7, BTW

Have you tried going to sepreate compaines and ordering indiviudal parts and making your own master rebuild?

with so many 350's out there I would have figured they would have the parts flowing out their ass.

I think the Summit dude I talked to was a moron, at least I hope he's not right. I thought about buying seperate pieces, but It'll cost so much it wouldn't be feasable..

I know that Rock Auto allows you to buy a complete long block or the individual parts (such as pistons), but I don't know if that is what your looking for. Just check around, and I'm sure you will.

Well, called Summit back, got an explanation.. The Oil ring groove is shallower on the 9C1 350 than any other 350. There is a kit for pickups 87-92 with the shallow groove, but it will not work with the police engine, and they aren't going to make a kit for the car..Dammit! So I call GM, they say sorry no parts are being made anymore...I didn't think I'd ever see the day when you couldn't rebuild a small block 350. GM and Summit and Jegs suggested getting custom pistons made, YEAH RIGHT! So anyone need a rock solid 700R4 and 8.5" LSD rear-end before I call the salvage yard n tell 'em to come get this worthless pile of bowtie...May she rest in peace.

I think I missed something; the new rings and pistons won't fit your cylinder bore because the current pistons have a shallow oil ring? Shouldn't make any difference in my mind. BTW, where can the car be picked up? :-)

I'm not exactly sure why it won't work, but summit said they tried it before and it bit them in the arse. I'm still not sure why if I was using new pistons, but....The car can be got in North East Arkansas. It's a shame since I just put $1400 in parts alone into the transmission, and the rearend has a 3 year old factory GM ring and pinion in it. I did all the bearings and LSD when I installed 'em...

Well, called Summit back, got an explanation.. The Oil ring groove is shallower on the 9C1 350 than any other 350. There is a kit for pickups 87-92 with the shallow groove, but it will not work with the police engine, and they aren't going to make a kit for the car..Dammit! So I call GM, they say sorry no parts are being made anymore...I didn't think I'd ever see the day when you couldn't rebuild a small block 350. GM and Summit and Jegs suggested getting custom pistons made, YEAH RIGHT! So anyone need a rock solid 700R4 and 8.5" LSD rear-end before I call the salvage yard n tell 'em to come get this worthless pile of bowtie...May she rest in peace.

Why not just run stock pistons in it then? Or go with a nice set of Keith Black hypereutectics - those work well - at least in my engine with 262k on them they do.

There's no way that a stock piston WON'T fit that engine - the block is the same regardless of what it's used in (with the exception of #bolts on main caps).

However, if you really don't want the hassle, I'll take the transmission. :)

Well, $600-$700 was all I was going to spend on it, and since my dream got shot to hell, I started daydreaming about my Monte again..so my funds are "shifting". If ya want the trans, ya gotta pull it. I've helped you already by killing the millions of super-hybrid yellow jacket/red wasps. Never seen a red wasp with a yellow belly. Don't let the color fool ya, them puppies was BAD! BTW, is the 9C1 LO5 a 2 or 4 bolt?

BTW, you come get the whole car, I'll throw in a pre-90(?) s/b 350, no heads or intake, that started smoking, so it was pulled. I can get the casting #'s off it tomorrow...

BTW, you come get the whole car, I'll throw in a pre-90(?) s/b 350, no heads or intake, that started smoking, so it was pulled. I can get the casting #'s off it tomorrow...

Unfortunately I'm in Arizona and I can't afford the trip to AR in either cash or time (although I've always wanted to visit that state and it would be cool to blow this place for a week or so) ...

What year Monte Carlo?

The passenger car L05 is a 2-bolt.

That 350 block - is it a one or two piece rear seal block?

Ah, Arkansas' a nice place, but the mosquitos and humidity make it rough... The Monte's a '96....No one wanted the poor girl, so I gave it a home..

Ah, Arkansas' a nice place, but the mosquitos and humidity make it rough... The Monte's a '96....No one wanted the poor girl, so I gave it a home..

Ah, what's in your sig. You have the Northstar V8 in it?

I bought a '93 Caddy w/ the 4.6 in it, but I never had time to swap it in(I'm a mechanic), so I sold it 'n' now I'm waiting on the supercharged 4.4 Caddy engine. Somewhere around 500hp and 500ft lbs of torque.. awesome...

I figured it out! Apparently, according to GM, the '91(not sure about others) 9C1 350 uses corvette pistons. Some camaro's used them also. They shot me a price of $100 each! OUCH!!! And to the best of his knowledge, the wristpin is located in a different spot than on a stock 350 which would raise or lower the piston in the bore. So I may not be able to fix it, but at least I know why now. Anyone need a good '91 9C1 with a rod knock? LOL

The 350 used in the 9C1 was no different than the 350 used in the passenger cars. The 350 was one of the most popular GM engines, so there is nothing about a 350 LO5 that would require special pistons. The LO5 9C1 version of the 350 had the L98 cam, it had a slightly better exhaust, it had alrger fuel injectors... and all that resulted in a boost from 180 fwhp to 205 fwhp. But the long block of the engine, copcar 9C1 or the old passenger car engine in grandpa's Buick --- they were the SAME.

If you have to rely on a parts sales person at Summit for that kind of info then you probably shouldn't be rebuilding an engine. You need to do more research on the web before relying on counter or phone help.

First off, your an asshole, so I don't want to see any more posts from you. Secondly, I've been SUCCESSFULLY building engines for 10 years now(I started when I was 16). Thirdly, I don't feel like dropping that much money on something that may not work, according to a well known GM service tech.

I wouldnt mind the trans. <_< got a price your asking for it?

Gimme a month, I'm tryin' to sell the whole car if I can't get confirmation on the rebuild project. If I decide not to rebuild or it doesn't sell, I'll part it out. I figure it'll be ridiculously cheap for a hi-po slushbox..

The 350 used in the 9C1 was no different than the 350 used in the passenger cars. The 350 was one of the most popular GM engines, so there is nothing about a 350 LO5 that would require special pistons. The LO5 9C1 version of the 350 had the L98 cam, it had a slightly better exhaust, it had alrger fuel injectors... and all that resulted in a boost from 180 fwhp to 205 fwhp. But the long block of the engine, copcar 9C1 or the old passenger car engine in grandpa's Buick --- they were the SAME.

If you have to rely on a parts sales person at Summit for that kind of info then you probably shouldn't be rebuilding an engine. You need to do more research on the web before relying on counter or phone help.
I would like to apologize to you... I totally agree with you, as does most other people I've spoken to. I don't see how a small block 350 could be anything but a 350, but after hearing all this other crap about $100 a piece pistons and corvette this and oil ring groove that, I can't afford to lay down the amount of cash I planned out on a non-refundable hope-and-guess. BUT, the way you said the last part hit me wrong after being in class working on junk all day, then going to work and working on more junk. I tend to get a little(understatement) touchy when I'm super-stressed, but I'm mellow now so..sorry.

About the only differences in TBI 350s that come to mind would be dished pistons (for lower CR) in a C/K/G truck engine vs eyebrow (valve relief) pistons on the passenger car. The dished pistons reduced the CR for detonation resistance in the face of heavier engine loads, as well as perhaps for lower octane requirements. Camaros got 2 bolt main L98 350s using 083 casting heads and the 773 cam; Caprice/Roadmaster/CustomCruiser also got the same 2 bolt block with swirl port 193 castings with the "peanut" cam. The Caprice 9C1 got the same 2 bolt engine but using the 773 cam.

The Corvette 350 (L98) was a 4 bolt main iron block (probably the same block as the truck) only the trucks were flat tappet (at least until 1994-1995 when there may have been carryover to the roller lifters) and the Vette got roller lifters (just like all GM v8s from 1988+). I don't think there was anything special about the Vette long block other than the 773 cam and the 113 casting number aluminum heads. The only special Vette engine of that era would be the dohc LT5 from the ZR-1 ... and I don't think there was any parts carryover between it and the L98.

If I really wanted to drive this nail home (and I don't), I would go looking for the GM part numbers for the main engine components in the Parts & Illustration book for the 1991-1993 models and then compare the std Caprice o the ones used for the 9C1 Caprice and for the Camaro and Corvette L98s. I'll bet the bearings, rods, pistons, rings etc are the same..... so the long block engines would only differ by the cam & heads.

A generic 350 rebuild kit ought to work fine for what you are doing. You don't need anything really fancy unless you are aiming for big power/abuse. And even if you aim for something better than stock (195 fwhp in 1991, 205 for 92-93) you will still need some custom ECM chip work to make it run well as all loads and speeds.

Hi
You can either replace your pistons with "standard style" 350 pre-86 or you can use the right rings from hastings, vin K "shallow oil groove" style.

http://www.fastengineparts.com/products.php?mid=12