4 Bolt 400
 

Fellas

Long time no see.

Buddy has a 4 bolt 400 block. Said to come out of a 69 Judge. Don’t have codes yet just saw pic of bottom end.

I can’t remember - did any RA III come with 4 bolt mains? Or only IV?

Scott

factory '69 usage RAIII blocks were 2bolt mains.

70 RA IIIs were 4 bolt caps along with RA IVs.Tom

You may find that it is a Service Replacement block
 

All of the Service Replacement (SR) 400cid blocks we've handled had 4-bolt mains, although I believe they were produced both ways.

I think Pontiac figured that if you managed to break a 2-bolt block, replacing it with a 4-bolt block might be a good idea.

As Tom S points out, ALL the factory 1970 Ram Air III and IV engines had 4-bolts. In 1969 it was only the RAIVs.

But Pontiac was always nice enough to produce something that challenges any absolutes we thought were undeniable.....

Thanks fellas. I’ll post the #’s when I get them.

Bulletpruf,

Welcome back. Look forward to your future posts. Always interesting and educational.

BTW, thanks for your service.

Jim

Thanks, Jim. I appreciate it.

Scott

Numbers yet? ;-)

Right, I guess Im not the only one looking for their correct lost 1969 RAIII motor.
Oh please, Oh please, Oh please be mine ;)

Humbler, are you the Craiglist searcher?

Guy was told that it came out of a 69 Judge. If so, perhaps it's a IV block. We'll see.

Some 1970 model year Ram Air III engines have the 9799915 block (9799914 with the 4 machined away and replaced with a 5), with the WS (manual) stamp on the front.

My February 1970 Lordstown produced 4 speed M-21, blue/blue deluxe interior TA that I have owned since 1979 has that, with the W well stamped but the S more faintly stamped. Block's casting date is early January.

Lordstown produced 70 Ta ?

He probably sees the 'L' figuring it's Lordstown?
(L is for Van Nuys )


:)

I stand corrected.

Was going from memory.

My 1970 Trans Am has the "N" - Norwood, Ohio.

https://www.hotrod.com/articles/norw...plant-reunion/

https://www.chevy-wiki.com/wiki/Norwood_Assembly

Yes, "L" is Van Nuys.

Question- how did they get an "L' designation, rather than say "V".

I believe the L for Van Nuys signified Los Angels but just a guess.

Factory literature indicates even the base GTO 400 with manual trans (WT) was four bolt main. I don't know if this was actually the case in production.

We've had a couple 1969 'WT' engines and four or five 1970 'WT" engines.
 

Every one of them had 2-bolt main caps.

And ALL of the 1970s were drilled for 4-bolt mains, but had 2-bolt caps. The 1969s did not have the extra holes drilled.

But you never know what Pontiac might have done.......

btw in my last post I forgot to say i was referring to the 70 model year, 69 was all 2 bolt except the RAIV but factory literature for 1970 model year says all GTO' engines except the base 400 with automatic (YS) had 4 bolt mains. Has anyone seen 1970 WT (350 horse 400 with manual trans) with 4 bolt mains?

I have original YS block in my 69 and it is drilled for 4 bolt mains

Members here have posted in the past first hand accounts of seeing 4-bolt 1970-WT engines;
From what I've understood, it wasn't the norm, but wasn't terribly unusual either.
From everything I have read suggests that pre-1970 400 blocks all had two bolt mains except for the RAI, RAII, & RAIV;
It reads as though starting in 1970 things changed a bit, as all the RAIII engines came with four bolt mains, and up through 1972 the odd 400 Firebird/GTO manual transmission engine has been found to have four bolt caps.
It also reads as though starting in 1970 (maybe this also applied to late 1969 blocks as well) all 400-4bbl engines were drilled and tapped for four bolt mains.
I am unsure as to when 400 blocks started to usually NOT be drilled and tapped for four bolt mains - although I'd wager a guess of 1973

Regarding the earlier comment:
I have not read this;
It reads as though the block was replaced with either an as correct one, or a readily available one.

HERE is the thread I recently created asking about SR blocks.

if you go to the other thread this has been discussed recently and I posted pics of 2 69 WS blocks that were drilled for 4 bolt but with 2 bolt caps. I have had several WT code 69 engines that were the same way drilled for 4 bolt but with 2 bolt caps.