402 head #'s??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMC69mnypit · 07-12-2005, 12:13 AM

Hey, does anybody know the more popular Head casting #'s used on our generation 402's? Or, if not the casting numbers themselves, were ours usually oval/square/peanut port, valve size, runner cc, open/closed chamber etc? Any info would be appreciated.

Thanks,
Brandon

dave3156 · 07-12-2005, 01:02 AM

I have a 1970 402. They are oval port heads. I can get the casting #s for you tomorrow, unless someone else has them handy.

55454 · 07-12-2005, 08:29 AM

www.mortec.com

GMC69mnypit · 07-12-2005, 11:21 AM

Dave3156, thanks for the info.

Yeah, I've been to Moretec and all of the other casting # sites, but they don't do a very good job of listing the heads used by model, and an even poorer job of listing the head configuration. Sure, there were probably half a dozen different head #'s used on our 402's in '72 alone, but I'm assuming since the HP rating was the same that the configuration of the heads was the same - i.e., 2.19/1.88 or ???/???, open/closed chamber, oval/rectangle/peanut port, runner cc, chamber volume, etc. That's the info I'm looking for. Just trying to get a rough idea what we had factory.

Thanks,
-Brandon

COBRO · 07-12-2005, 09:56 PM

My 72 402 had 820 heads which is shown to used from 71 thru 84 on 402 and 454. All BBC heads used up thru 72 in trucks were oval port heads and had 2.06 and 1.72 valves,most but not all were open chamber,the 366/427 tall deck used closed chambers. Rectangular port heads were never used on any truck engines and the peanut port heads didnt show up until the late 80s. The best of the bunch for flow are the 049 so I hear. HTH::::::CB

dave3156 · 07-13-2005, 05:29 PM

Here are all the numbers I could find on my 1970 402 heads which came from a 1970 3/4 ton truck: 3975950, GM4T, C28 70 and the words: M TRUCK

Hope this helps.

drink2mny · 07-13-2005, 10:16 PM

Mine are 820, original to my 402..

Here's a good heads link
http://www.roadsters.com/bbc/#oval

55454 · 07-15-2005, 07:41 PM

Many 402's came with semi-closed. If you put a set of closed chambered heads on a 454
it will give free horse power (hardened seats). Opinion only not fact.

Tommy

55454 · 07-16-2005, 08:14 AM

I dont know the spec's, but over my 25 years of collecting, with the exclusion of rectangle ports, 049's and 781's which pretty much flow the same but the 049 is an older casting are the best for the money on a 454. Unless you want the closed chambered heads and can afford the cost because 40 years later they are desirable to the muscle cars not to mention rebuilding them for todays gas. Like I said before I am not an expert it is only a hobby, but this is the best set-up I can afford, without expensive rect, cc or after market.

Thanks Tommy

07-12-2005, 12:13 AM	#1
GMC69mnypit !Women...!!!! Join Date: Jan 2005 Location: South of Hays, Kansas Posts: 40	402 head #'s??? Hey, does anybody know the more popular Head casting #'s used on our generation 402's? Or, if not the casting numbers themselves, were ours usually oval/square/peanut port, valve size, runner cc, open/closed chamber etc? Any info would be appreciated. Thanks, Brandon __________________ '69 GMC 1/2T LWB 2WD '02 Silverado 2500HD 4X4 '79 ElCamino SS

07-12-2005, 11:21 AM	#4
GMC69mnypit !Women...!!!! Join Date: Jan 2005 Location: South of Hays, Kansas Posts: 40	Dave3156, thanks for the info. Yeah, I've been to Moretec and all of the other casting # sites, but they don't do a very good job of listing the heads used by model, and an even poorer job of listing the head configuration. Sure, there were probably half a dozen different head #'s used on our 402's in '72 alone, but I'm assuming since the HP rating was the same that the configuration of the heads was the same - i.e., 2.19/1.88 or ???/???, open/closed chamber, oval/rectangle/peanut port, runner cc, chamber volume, etc. That's the info I'm looking for. Just trying to get a rough idea what we had factory. Thanks, -Brandon __________________ '69 GMC 1/2T LWB 2WD '02 Silverado 2500HD 4X4 '79 ElCamino SS

07-13-2005, 05:29 PM	#6
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	Here are all the numbers I could find on my 1970 402 heads which came from a 1970 3/4 ton truck: 3975950, GM4T, C28 70 and the words: M TRUCK Hope this helps. Last edited by dave3156; 07-14-2005 at 12:14 AM.

07-13-2005, 10:16 PM	#7
drink2mny Registered User Join Date: Jun 2003 Location: spokane wa Posts: 2,189	Mine are 820, original to my 402.. Here's a good heads link http://www.roadsters.com/bbc/#oval __________________ Support The Board

07-12-2005, 01:02 AM	#2
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	I have a 1970 402. They are oval port heads. I can get the casting #s for you tomorrow, unless someone else has them handy.

07-12-2005, 08:29 AM	#3
55454 55454 Join Date: Mar 2005 Location: Lafayette La. Posts: 340	www.mortec.com

07-12-2005, 09:56 PM	#5
COBRO Active Member Join Date: Jan 2005 Location: RDM,Oregon Posts: 285	My 72 402 had 820 heads which is shown to used from 71 thru 84 on 402 and 454. All BBC heads used up thru 72 in trucks were oval port heads and had 2.06 and 1.72 valves,most but not all were open chamber,the 366/427 tall deck used closed chambers. Rectangular port heads were never used on any truck engines and the peanut port heads didnt show up until the late 80s. The best of the bunch for flow are the 049 so I hear. HTH::::::CB

07-15-2005, 07:41 PM	#8
55454 55454 Join Date: Mar 2005 Location: Lafayette La. Posts: 340	Many 402's came with semi-closed. If you put a set of closed chambered heads on a 454 it will give free horse power (hardened seats). Opinion only not fact. Tommy

07-16-2005, 08:14 AM	#9
55454 55454 Join Date: Mar 2005 Location: Lafayette La. Posts: 340	I dont know the spec's, but over my 25 years of collecting, with the exclusion of rectangle ports, 049's and 781's which pretty much flow the same but the 049 is an older casting are the best for the money on a 454. Unless you want the closed chambered heads and can afford the cost because 40 years later they are desirable to the muscle cars not to mention rebuilding them for todays gas. Like I said before I am not an expert it is only a hobby, but this is the best set-up I can afford, without expensive rect, cc or after market. Thanks Tommy



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