Peanut port or Large Oval???? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tomsC10R · 01-25-2004, 07:54 PM

Does anyone know off hand if these are the peanut port heads or the large oval port heads?

The casting number is 473328, which according to Mortec is a 68-69, "oval", Open, from a 366 tall deck.

Here's all the info on the passenger side head starting from the rear.
B1-78
GM1T
TRUCK
473328

Oh yeah, is there any difference between heads from a tall deck block compared to heads from a regular deck block? My block looks to be a 402 regualar deck.

Thanks

*1972C10* · 01-25-2004, 07:57 PM

I was lead to belive they didnt have the peanut port untill mid 80s

jamis · 01-25-2004, 09:12 PM

The only peanut ports I have ever seen are actually round in shape not oval. None of the diffrent casting # research pages I have looked at distinguish the diffrence. They all say oval but I have seen the small round ports that I consider to be the peanut port.

67dragtruck · 01-25-2004, 09:15 PM

I agree, I thought the peanut ports came along in the 80's

Burnsman · 01-25-2004, 10:44 PM

I have had a few of these 366's. The heads were usually large oval with huge combustion chambers (somewhere around 120cc).

tomsC10R · 01-26-2004, 12:10 AM

Cool, thanks for all the replies. From what everyone's said, it sounds like my new setup should bolt right on. I guess I'll know for sure when I get around to taking the old manifold off.

Thanks again.

stepside454 · 01-26-2004, 12:26 AM

I think peanut ports started in 76

demi · 01-26-2004, 02:02 PM

Mark IV, Gen V, Gen VI small oval dimensions
are 1.45 x 1.60 and were made from 1976 on.
Large oval dimensions are 1.82 x 1.60.

01-25-2004, 07:54 PM	#1
tomsC10R Registered User Join Date: Nov 2003 Location: Wisconsin Posts: 281	Peanut port or Large Oval???? Does anyone know off hand if these are the peanut port heads or the large oval port heads? The casting number is 473328, which according to Mortec is a 68-69, "oval", Open, from a 366 tall deck. Here's all the info on the passenger side head starting from the rear. B1-78 GM1T TRUCK 473328 Oh yeah, is there any difference between heads from a tall deck block compared to heads from a regular deck block? My block looks to be a 402 regualar deck. Thanks __________________ Tom 1968 C10 LWB. 402 BB, Holley MPI, 700R4. 4wheel Hydroboost Disk Brakes.

01-25-2004, 09:12 PM	#3
jamis F.A.S.T. president Join Date: Sep 2003 Location: Florida Posts: 1,883	The only peanut ports I have ever seen are actually round in shape not oval. None of the diffrent casting # research pages I have looked at distinguish the diffrence. They all say oval but I have seen the small round ports that I consider to be the peanut port. Last edited by jamis; 01-25-2004 at 09:14 PM.

01-25-2004, 09:15 PM	#4
67dragtruck Registered User Join Date: May 2001 Location: Bethlehem, GA, USA Posts: 389	peanuts I agree, I thought the peanut ports came along in the 80's

01-25-2004, 10:44 PM	#5
Burnsman Chevy Freak Join Date: Sep 2002 Location: Meadville, Pa. Posts: 2,804	366 heads I have had a few of these 366's. The heads were usually large oval with huge combustion chambers (somewhere around 120cc). __________________ 69 GMC SWB, 350 70 Chevy LWB, 350 55 chevy gasser, 461 73 Camaro, 496 67 RS Camaro, 406 64 Chevelle, 588 71 Nova, 565 67 Camaro, 461

01-26-2004, 12:10 AM	#6
tomsC10R Registered User Join Date: Nov 2003 Location: Wisconsin Posts: 281	Cool, thanks for all the replies. From what everyone's said, it sounds like my new setup should bolt right on. I guess I'll know for sure when I get around to taking the old manifold off. Thanks again. __________________ Tom 1968 C10 LWB. 402 BB, Holley MPI, 700R4. 4wheel Hydroboost Disk Brakes.

01-25-2004, 07:57 PM	#2
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	I was lead to belive they didnt have the peanut port untill mid 80s

01-26-2004, 12:26 AM	#7
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	I think peanut ports started in 76 __________________ 75 GMC C-15 short/step factory 454, lowered

01-26-2004, 02:02 PM	#8
demi Registered User Join Date: Sep 2003 Location: Arizona Posts: 305	Mark IV, Gen V, Gen VI small oval dimensions are 1.45 x 1.60 and were made from 1976 on. Large oval dimensions are 1.82 x 1.60.



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