Stock valve covers for big blocks inter-changable? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71CHEVYSHORTBED402** · 06-02-2015, 12:26 AM

The 1971-72 402 engines have a push in oil cap from the factory. The 1969-70 big blocks have the twist/turn style oil cap.

My 402 was rebuilt with 396 heads, and the valve covers came with those heads. Unfortunately, I no longer have the original valve covers that were on the original heads, but I think I'd like to find a pair. What I'm wonder is, do you know if the bolt patterns are the same for both types, and is there a clearance concern?

ho70 · 06-02-2015, 12:45 AM

tall valve covers will hit your ac bracket on the passenger side (at least mine did)
big block valve covers are interchangeable, a higher lift cam and some aftermarket rockers may require tall valve covers

**special-K** · 06-02-2015, 07:27 AM

Yes, all 396/402 valve covers have the same bolt pattern and are fully interchangeable.

davepl · 06-02-2015, 12:34 PM

True for all of the "old" big blocks. I have not looked at an 8.1L to see if they changed, but otherwise they should all be the same.

If going to stock covers, try to find real ones. Repros may not have oil drippers (if big blocks do, can't recall). And I'm not sure if they all have the brake booster clearance on the driver side. My car (B-Body) has the factory valve covers and the big diameter booster.

Jonlopes · 06-02-2015, 03:53 PM

Also most aftermarket steel valve covers are so thin that the ends will warp up and leak if they are tightened a little too much. Of course they will also leak if too lose. I recommend factory valve covers or cast aluminum. I also personally like to use Permatex non-hardening sealer on the gaskets.

**71CHEVYSHORTBED402** · 06-02-2015, 11:17 PM

Thanks for all the replies. If I recall, during the rebuild, the valve covers on my 396 heads (69-70) are more rounded and "fatter" than the those that were on my 402 heads (71-72), which have a more square appearance. I'm fairly comfortable saying both sets of valve covers were/are stock. Here's a picture of the 69-70 version on my truck. I'd like to find a clean pair of OEM 71-72.

Yeah it needs a bath. It's usually clean. It's the exterior that I haven't washed in I don't know, 15 years or so. I'm tearing into it very soon any way. Someday the A/C will be reassembled.

**special-K** · 06-03-2015, 07:19 AM

'70s were 402, so there ya go...same/same.

06-02-2015, 12:26 AM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,188	Stock valve covers for big blocks inter-changable? The 1971-72 402 engines have a push in oil cap from the factory. The 1969-70 big blocks have the twist/turn style oil cap. My 402 was rebuilt with 396 heads, and the valve covers came with those heads. Unfortunately, I no longer have the original valve covers that were on the original heads, but I think I'd like to find a pair. What I'm wonder is, do you know if the bolt patterns are the same for both types, and is there a clearance concern? __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025

06-02-2015, 12:45 AM	#2
ho70 Registered User Join Date: Nov 2013 Location: Winnipeg, Mb Posts: 1,115	Re: Stock valve covers for big blocks inter-changable? tall valve covers will hit your ac bracket on the passenger side (at least mine did) big block valve covers are interchangeable, a higher lift cam and some aftermarket rockers may require tall valve covers

06-02-2015, 07:27 AM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: Stock valve covers for big blocks inter-changable? Yes, all 396/402 valve covers have the same bolt pattern and are fully interchangeable. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

06-02-2015, 12:34 PM	#4
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Stock valve covers for big blocks inter-changable? True for all of the "old" big blocks. I have not looked at an 8.1L to see if they changed, but otherwise they should all be the same. If going to stock covers, try to find real ones. Repros may not have oil drippers (if big blocks do, can't recall). And I'm not sure if they all have the brake booster clearance on the driver side. My car (B-Body) has the factory valve covers and the big diameter booster. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

06-02-2015, 03:53 PM	#5
Jonlopes Registered User Join Date: Mar 2013 Location: Anaheim Hills, CA Posts: 323	Re: Stock valve covers for big blocks inter-changable? Also most aftermarket steel valve covers are so thin that the ends will warp up and leak if they are tightened a little too much. Of course they will also leak if too lose. I recommend factory valve covers or cast aluminum. I also personally like to use Permatex non-hardening sealer on the gaskets. __________________ 1971 Cheyenne Big Block Longhorn

06-02-2015, 11:17 PM	#6
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,188	Re: Stock valve covers for big blocks inter-changable? Thanks for all the replies. If I recall, during the rebuild, the valve covers on my 396 heads (69-70) are more rounded and "fatter" than the those that were on my 402 heads (71-72), which have a more square appearance. I'm fairly comfortable saying both sets of valve covers were/are stock. Here's a picture of the 69-70 version on my truck. I'd like to find a clean pair of OEM 71-72. Yeah it needs a bath. It's usually clean. It's the exterior that I haven't washed in I don't know, 15 years or so. I'm tearing into it very soon any way. Someday the A/C will be reassembled. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025

06-03-2015, 07:19 AM	#7
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: Stock valve covers for big blocks inter-changable? '70s were 402, so there ya go...same/same. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~



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