78cutlass

What's your opinion of the EARLY BBO 400? Do they make good street/strip motors? I'd like to put together a nice pump gas friendly BBO ("boulevard bruiser"). I've read the early 400's are more desireable. I have access to an early 400 ("E" block). Also, I read SBO W-31 flat top pistons fit early 400's.

Techmaven

Early 400 is a shadow of the 425 except for 1/8" smaller pistons. It has a forged crank and if it's a 67 442 block it has the 2.067" intake valves...Other years were 2.00".

350 pistons would require a .057 overbore.

Makes a fine street/strip engine.

66400

It has a forged crank and if it's a 67 442 block it has the 2.067" intake valves...Other years were 2.00".

Correction........66 400 heads all have large intake valves. Henry

Oldsmaniac

The 400 is desireable to those who want to put their cars/442's back as stock and may be missing the 400. A 425 or 455 can be gotten fairly easily and would make a better build. Sell the 400

Techmaven

Not according to my shop manuals. Who knows, they could be wrong.

88 coupe

Were your "shop manuals" printed in another hemisphere?

Norm

wmachine

X2. I have to agree. Simple logic is that with the 400 being a 425 with a smaller bore, and the 425s are more plentiful and not stock in any 442, there isn't any compelling reason to forgo the extra cubic inches.

wmachine

Well, no matter where the manuals come from, the heads don't have to match the blocks, and more importantly, using '67-'69 big valve C heads will work better for you.

88 coupe

It would take a very specific head, if the valves were in the block.

Norm

wmachine

Concentrate Norm, I *know* you can make value added statements!

aliensatemybuick

Of course, you don't have to "settle" for 400 c.i. as I understand (from those who have done it) that there is plenty of "meat" in the early 400 casting to overbore by 1/8 inch and have a 425.

Of course, then you will have merely a "lowly" 425, which as some have recently said is no substitute for a 455, but that is another matter...

Techmaven

Everywhere I checked for info on 1966 400/425 heads say they have 2.00 intakes including the 442's....1967 used 2.00 except for 442's which have 2.067.

And for the record, I have factory GM shop manuals.

wmachine

'66 442s did indeed have 2.067 intakes. I'm sure the GM shop manuals you have are dated prior to actual '66 production. I'm guessing that they originally were slated to be 2.00, but were increased just prior to production. There is a mid-year 442 brochure that specifies the 2.067 for one source.
Further proof is offered by the June '67 Olds Parts & Acc. Catalog that shows all '66-'67 442, Starfire, Toro, etc. have exactly the same intake valves.

Bear in mind that all ('60s, at least) shop manuals are published well in advance of production, and I can't think of a year that has more than the one early edition. Changes are generally covered by Service Bulletins.

66400

Starfires used small intake valves.

Henry

wmachine

According to the parts book the June '67 Olds Parts & Acc. Catalog, the '66 and '67 Starfire engine intakes are the same as the 442s.
I believe that is accurate, Henry.

Redog

Early 400's could rev upto 7000,

eff said

gmrocket

i bought a turnpike cruise option cutlass long time ago for parts and it had the 2brl 400, small valve B heads. i think you could also get the 400 in a vista cruiser with 2brl&thay also had 2.00" valves? i have some small valve B heads now that i picked up recently ,where would they be from?

wmachine

Good question. First, the B heads are '66, and wouldn't have been original on the TC Cutlass 400, which would have to have been a '67 engine.
There are small and big valve B heads ('66) and small and big valve C heads ('67-'69). *Generally* speaking, the 442s, and higher compression 400s, 425s and 455s like the Toros and Starfire motors got the larger valves. I'd have to go back to the books for exactly where the line is drawn from small to large, *but* there has "always" been some evidence that there was some infiltration of small valve heads on some large valve applications (and who knows, possibly the other way around). This would not have been a far fetched possibility, as there is no external identification for valve size. The only way to be sure is to measure, though some well trained eyes can look at the valves and/or the seats and tell.

Warhead

Intake valve size is 2.072,
not 2.067.

aliensatemybuick

While I do not have access to the books you have, I must respectfully disagree with big valves in Starfire engines based on personal experience.

wmachine

No, not in '66-'67.

wmachine

I know this has been the case in '65, but should not be the case in '66-'67.
I do think this is a specific area where there have been smaller valves found in applications that were *supposed* to have large valves as I previously said. So finding actual exceptions are certainly possible.

aliensatemybuick

Again, respectfully, I have seen 2 '66 Stafire engines apart with small valves, and have spoken with others who say they have seen more still and that they have all had the smaller intake valves. Thus I tend to doubt that what I saw was the exception rather than the rule. I refer you to the following threads on another forum that tend to support my stated belief regarding '66 Starfire intake valve size based on factory literature:

http://www.realoldspower.com/phpBB2/...ic.php?t=24745
http://www.realoldspower.com/phpBB2/...663ef92dc5ddc9

I know I am talking about '66 Stafire engines here; while I understand that the Stafire engine option (if not the car!) was available in 1967, I'm not sure I have ever actually seen one nor do I know what the factory stated specs were.