1970 Z28 intake, carb, heads and air cleaner find

[Furback]

Here is an old ad for a pair of 3881492 heads. I think the 1 in the casting number is missing and there is a space there for it.




street stock 77 is offline 100 Post Senior Member


Join Date:Aug 2010Location:chillicothe ohioPosts:36


Default SMALL BLOCK CHEVY HEADS



1ST SET CASTING NUMBERS 3911032

1968 1969 307CI. OR 327CI.

70CC 1.72 INT. 1.5 EXT. STRAIGHT PLUG 75.00 MAKE OFFER THEY ARE NUMBERS MATCHING



2ND SET CASTING NUMBERS 3881492

1970 LT1 CAMEL HUMP 350 CI.

SCREW IN STUDS AND GUIDES

64 CC ACESSARY HOLES STRAIGHT PLUG 225.00 MAKE OFFER THEY ARE NUMBERS MATCHING
LOCATED IN CHILLICOTHE OHIO CALL 740 703 6451

NEITHER SET OF HEADS HAVE BEEN ON RACE MOTORS OR HOGGED OUT
THEY ARE STOCK SO WHAT YOU DO WITH THEM IS YOUR CHOICE

THANKS.

[luzl78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Charley Lillard</div><div class="ubbcode-body">Am I the only one that thinks it reads 388 482 ? </div></div>. All three 8's in the photo are the same. Doesn't look like a 9.

[Furback]

The throttle cable bracket part number is 3980982.

[ted]

I have a straight plug head 3991492 dated K30 1 with 1.94s, pressed in studs and acc. bolt holes.
Looks like Mr. Furback is from New Brunswick and I am from Quebec. Could these somewhat similar geographical locations have anything to do with this topic?? Just an idea, maybe a bad one, eh boys??
I have 3991492 and the head below 3973370 as camel humps on my parts listing.

Here is another one, 3973370 dated D23 0 straight plug 1.94s was on the same 355 engine I bought years ago.
Obviously they are not date-matched, but 3973370 is that a popular U.S. head or an oddity of some sort??
Thanks!
Ted

[68moz28rs]

Hey Ted, those are good heads. The 370 were a Canada only production head. Not sure but I think they were over the counter and came on some 350/300 or Z/28.?

[Furback]

The 370 head is a &quot;Canada&quot; casting. Commonly found on Canadian built Pontiacs like the Paressien 2+2 cars, on the 350 / 300 horse engines in 1969 and 1970. I have had lots of those. They are very good casting to port as they are cast on the heavy side. 492 straight plug castings are quite common in the 1.94 valve version. I have heard that some 370 castings have been found on Canadian built Chevelles that were sold in USA. That would be cars with the 300 horse 350. Never saw any 370 castings in 2.02 version.

[Furback]

Another pair of those 492 straight plug heads that were never produced. LOL



http://www.ebay.com/itm/492-heads-/2...GG&amp;vxp=mtr

[Lynn]

I believe the 3991492 casting came in straight plug and angle plug. The better angle plug heads (especially if porting) are the 292.

[Hotrodpaul]

The 492 heads were primarily an over the counter and warranty replacement head. My 70 Z28 has a CE warranty replacement short block and one original 186 and 492 replacement head. Second owner said the engine was overheating around 1972 so he brought it to the local Chevy dealer and they installed the warranty short block and head.
The 492 angle plug head and 292 Turbo heads are different castings. The 292 head has an improved Intake port with additional material and volume for porting, and was the best head for racing use in the mid to late 70's. I have both and plan to flow test them on my Superflow bench sometime in the future. I will post the results when I get the time.

Paul

[Lynn]

Thanks Paul. Is the full casting number on the 492 replacement head different from the 492 angle plug head? Perhaps that is where the confusion lies.