69 L48 - 2 or 4 bolt mains

[KurtS]

I wanted to know if others have seen 1969 L48 engines with 2 bolt mains. Most have 4 bolts, but some are 2 bolts. How common is this??

[ko-lek-tor]

I have had several 1969 and 1970 L48 engines over the years. The ones that came out of full bodied cars,like Impalas (it was a 1970), were two bolt jobs. The Camaro,Nova ones I have or had were four bolt. Never actually had a 1969 two bolt,so this may not answer your ?

[lynnbilodeau]

Kurt:
I don't have a lot of experience, but have dismantled maybe 10 to 20 of the 69 L48's, mostly from full size cars.  Some 350's from pick ups.   I wish I had taken notes, pics etc.  Most were four bolts.  I know I was always a bit surprised to see 2 bolts.
Going from memory only (dangerous) it seems like most, if not all the Flint cast and assembled motors were 4 bolt.  Also, after the change to the 3970010 block, I don't remember EVER seeing a 2 bolt block, at least not on a 69.
Remember one full size car with a first week of Jan (69) engine that was four bolt, but did not note if it was T or V coded.  Only reason that one sticks in my head is that it had one 041 head and one 186 head, and all indications were they were both original to the car.

Wish I could be more help.

[KurtS]

Hmm, I had assumed since the hp ratings were the same, there wouldn't be differences between full-size and smaller cars. But I have an early 69 L48 full-size block and it's a 2-bolt.....
Had 186 heads too.

Thanks!

[tmodel66]

This is not news to anyone but back in the day when we went hunting for engines to put away for builds later on we always sought out trucks and Impalas. About 95% of the time they were 4 bolt. Sometimes a station wagon but we would drop the pan to check first and it was hit and miss with those on 4 bolt.

[69Z28]

My first 69 SS350 was a 4 bolt block with steel crank. I remember this car very well. Check out my story.

Back in 75 my first 69 Camaro was an early built car, SS 350, black, non-vinyl top, standard black interior, red SS stripes, short rear spoiler, 3 speed on the floor, no console or other gauges, 12 bolt 3.55's, 350/300 engine. I pulled the engine to rebuild it and dropped in a built 327. What a dumb A I was, but I didn't know what was what then. When I tore the engine apart it had 4 bolt mains and a steel crank. The block sat in my bedroom closet for months and when I moved to base housing at Dover AFB my memory gets a little foggy here. Not sure what happened to it. I do know that I had a friend remove the 3 speed and install a 4 speed but he kept the 3 speed. I believe it was a saginaw. I know this post is about the 2 or 4 bolt question but the more I find out about my Z the more I remember how much of an idiot I was when I had the SS. Heck I even installed Thrush side pipes that had the louvers in the covers on it. Sounded too much like a corvette, so I removed and sold them. I still have the original chrome aftermarket tailpipes that where on that car too. I think they were Wagners but not sure. If I'm not mistaken it was sold to some kid in Havre Degrace Maryland and totaled shortly after I got orders to go to England. I was really sad when I heard that. I think I have a pic of me, my first wife and my oldest boy standing in front of that car somewhere. I'll look if anyone is interested.

[x77-69z28]

Always interested in old photos of our cars!

[ggtsvnv]

I have had several 67-72 L48's out of Camaro's, Chevelle's, Nova's, Monte Carlos,  and full sized chevys. I'm not going to say they didn't exist in 2 bolt mains, but all of the 67 to 70 blocks I have seen were 4 bolt. Starting in 71 and up I have seen both 4 and 2 bolt, but more of the two bolt variety.  A couple of years back I sold a 71 SS 350 Camaro it was a two bolt, and I at present have a 2 bolt L48 out of a 71 Monte Carlo. I always thought that it might have had something to do with the drop in compression ratio that started in 71 on H/P engines.

[zman1969]

NOT L48-  I was under the impression that all 4 barrels were 4 bolt in 1969 but I have a 250hp out of a chevelle wagon and it was a 2 bolt the difference was 441 heads- low compression and single exhaust Vs. L48

[JKZ27]

I have an L48 from a 69 Impala wagon and its a two bolt. I have not yet pulled the pan on my Camaro to check...may try a bore scope.

John

[69Z28]

Sorry guys haven't found the pic of my 69 SS. I have 'A LOT' of pictures to look through. If I remember correctly the 350/300 in my SS was 4 bolt but it had the 441 heads and q-jet carb. No camel humps.

[crobjones2]

I know my L48 is a 4-bolt. When I was in HS , I had a friend who had a 69 Impala with a 350/300? and he had a 2 bolt. The only thing we could come up with for the difference was the block castings were different

[69z28rsbilly]

All 1969 1970 chevy 350 truck motors i have seen have been 4 bolt mains, all of the big body chevys(caprice impala) 350's have been 2 bolt mains.........

[festival]

Kurt,

My 05A Z-11 has a Saginaw 010 block cast on April 6th with 186 heads.    It is a assembled Flint engine with a 4 bolt too.   I hope this helps.