283 & 327 w/4 bolt mains

[Rex T.]

Does anyone have any original GM 4 bolt main caps for a small journal crank? These are the straight bolt type, not splayed.

[Michael H.]

Re: 283 & 327 w/4 bolt mains

Does anyone have any original GM 4 bolt main caps for a small journal crank? These are the straight bolt type, not splayed.

Rex,

Unless there's something I'm forgetting about, I don't think GM ever made a small journal 4 bolt cap/engine. The first large journal was 68 and the first 4 bolt cap was 69.

[Jack H.]

Re: 283 & 327 w/4 bolt mains

Rex,

Unless there's something I'm forgetting about, I don't think GM ever made a small journal 4 bolt cap/engine. The first large journal was 68 and the first 4 bolt cap was 69.

This is my recollection as well. Of course there are aftermarket 4 bolt caps for the small journal configuration (at least there were, haven't checked in a while). I have also seen original GM 4 bolt caps (from later models) retrofitted to earlier 283/327 blocks, but that included use of the later large journal crank.

[Rex T.]

Re: 283 & 327 w/4 bolt mains

Rex,

Unless there's something I'm forgetting about, I don't think GM ever made a small journal 4 bolt cap/engine. The first large journal was 68 and the first 4 bolt cap was 69.

No, you're not forgetting anything Mike and no, GM never made a "production" (for sale to the general public) 4 bolt small journal block. I'll leave it at that for now.............................

[Scott M.]

Re: 283 & 327 w/4 bolt mains

Program Engineering makes the best ones if you are looking to install some.

[Rex T.]

Re: 283 & 327 w/4 bolt mains

Thanks Scott. I just loooked at their website and they seem to have nice items, a bit pricey, but looks like good quality American-made products. I'd "like" to find some original GM pieces, but may have to resort to the aftermarket.

Thanks for the tip.

[Scott M.]

Re: 283 & 327 w/4 bolt mains

They are the only company that I'm aware of that makes the 283/327 SJ billet caps and you can usually find the center 3 caps for about $200.

[Joe R.]

Re: 283 & 327 w/4 bolt mains

Rex,

I believe that GM did make a 327 small journal and large journal from the casting 3914678 in 1968.

Iffin that is true the four bolt caps would probably fit that block.

Of course the block would have to be align bored but I'm sure you already knew that.

Need to find an old dude in the machine shop. Bet he can rattle off the info you need without taking a breath.

JR

[Rex T.]

Re: 283 & 327 w/4 bolt mains

They are the only company that I'm aware of that makes the 283/327 SJ billet caps and you can usually find the center 3 caps for about $200.

OK..................I misinterpreted the pricing. I thought it was $200 + per cap. I'll reconsider those.
Thanks

[Rex T.]

Re: 283 & 327 w/4 bolt mains

Rex,

I believe that GM did make a 327 small journal and large journal from the casting 3914678 in 1968.

Iffin that is true the four bolt caps would probably fit that block.

Of course the block would have to be align bored but I'm sure you already knew that.

Need to find an old dude in the machine shop. Bet he can rattle off the info you need without taking a breath.

JR

Joe, you are 100% correct about the large and small journal blocks. However......................I don't think any of them were 4 bolt main blocks. I believe Mike is correct with his comment that they didn't introduce the 4 bolt blocks until 1969.

This request was just a shot in the dark, hoping to find that "needle, not in the hay stack, but in the hay field".

[Joe L.]

Re: 283 & 327 w/4 bolt mains

Joe, you are 100% correct about the large and small journal blocks. However......................I don't think any of them were 4 bolt main blocks. I believe Mike is correct with his comment that they didn't introduce the 4 bolt blocks until 1969.

This request was just a shot in the dark, hoping to find that "needle, not in the hay stack, but in the hay field".

Rex------


I can confirm that there were never any 4 bolt main caps used for any PRODUCTION small journal small block. The first uses for PRODUCTION engines were 1969 350's with 4 barrel carburetors and 1969 302's used in Z-28's.

Also, I can find no information that GM ever offered a 4 bolt small journal main cap in SERVICE, either as a GM Performance Parts item or otherwise.

[Clem Z.]

Re: 283 & 327 w/4 bolt mains

Does anyone have any original GM 4 bolt main caps for a small journal crank? These are the straight bolt type, not splayed.

on 283 and 327 when no 4 bolt caps were available we installed a square steel bar across the bottom of the cap after machining the caps flat for the steel bar to rest against. we used studs to install the bars and caps.

[Rex T.]

Re: 283 & 327 w/4 bolt mains

Please forgive me everyone..............................I must have had a "senior moment". I could have sworn that I had a 283 block that had factory supplied 4 bolt mains. I'll keep looking thru my collection of parts and if I find it I'll post some pics..........................I know it's here somewhere.........................

[Michael H.]

Re: 283 & 327 w/4 bolt mains

Please forgive me everyone..............................I must have had a "senior moment".

Rex,

We all have those "senior moments". I have lots of em. Just wait till ya get old, like me. (I'm not as old as ol Duke though)

I bought a GPS so I can now find my way home from the store.

[Joe L.]

Re: 283 & 327 w/4 bolt mains

Please forgive me everyone..............................I must have had a "senior moment". I could have sworn that I had a 283 block that had factory supplied 4 bolt mains. I'll keep looking thru my collection of parts and if I find it I'll post some pics..........................I know it's here somewhere.........................

Rex------


If yo find one, you can be ABSOLUTELY CERTAIN that it was a post-factory conversion.