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1991 chevy 350

12K views 11 replies 6 participants last post by  machine shop tom 
#1 ·
My buddy is giving me a sbc 350 out of a 1991 chevy 3/4ton pickup. Does anybody know if this engine has a roller cam in it. I know all 350's from 1996 and up had them but im not sure about a 1991. Its got 360,000 miles on it. I figured I could use it for a rebuild if it had a roller cam in it.
 
#8 ·
curtis73 said:
Only way to be sure is to check. Some were flat cam blocks with flat cams, some were roller blocks with flat cams, and some were roller/roller.

From what I've heard, most of them are flat cams/roller block between 87-95
So if it was a rollerblock/flatcam would it be hard to convert it to roller? Would you have to machine the bolt holes that hold the rollers in the valley? I think its called a "spider plate" or something. Or is it a easy conversion?
 
#9 ·
I have never seen a roller cammed 87-95 TBI truck engine from the factory. All the 50+ of these engines I have been into have had flat tappet cams. I have heard of one person say that some had rollers but have yet to see it.

Some of the blocks are factory hydraulic roller ready,some just need the three guide retainer holes and two cam thrust plate holes drilled and tapped,and some are flat tappet only. There seems to be no pattern as which years have what.

If your block is roller ready,you will need GM part# 12371042 which consists of 16 hydraulic roller lifters,8 lifter guides,1 retainer,and three retainer bolts.

Part# 12371041 is the pushrod kit

Part#12371043 is a single roller timing set that includes a roller chain,cam gear,crank gear,thrust plate,and thrust plate bolts.

You can also find these parts used on Ebay for a fraction of the cost.
 
#10 ·
GMC boogie said:
I have never seen a roller cammed 87-95 TBI truck engine from the factory. All the 50+ of these engines I have been into have had flat tappet cams. I have heard of one person say that some had rollers but have yet to see it.

Some of the blocks are factory hydraulic roller ready,some just need the three guide retainer holes and two cam thrust plate holes drilled and tapped,and some are flat tappet only. There seems to be no pattern as which years have what.

If your block is roller ready,you will need GM part# 12371042 which consists of 16 hydraulic roller lifters,8 lifter guides,1 retainer,and three retainer bolts.

Part# 12371041 is the pushrod kit

Part#12371043 is a single roller timing set that includes a roller chain,cam gear,crank gear,thrust plate,and thrust plate bolts.

You can also find these parts used on Ebay for a fraction of the cost.
Thats so wierd. I own two s10's. They are '89 and '91 years. They both have the 4.3 and the '91 has a roller cam and I'm pretty sure the '89 has it too. Its funny they do roller 4.3's but not the 350's of the same year. I will still look for a roller block even if this one turns out to be non roller.
 
#12 ·
Many of the 1987-1995 blocks are have the bosses and are tapped for the spider plate and have the boss for the camshaft retainer plate on the front of the block. While the trucks didn't use the roller cam and lifters, some Firebird and Camaros did.

It's a crapshoot whether or not the truck blocks have the bosses and such for the roller cam set up. I just lucked into a 4 bolt main block that is also set up for the roller cam.

tom :thumbup:
 
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