Big Block perches 1972 GMC 2500 LS swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1972GMC2500 · 05-05-2016, 10:46 AM

I'm trying to get everything ready to transplant a 5.3l LS into my 1972 GMC 2500. It has a 402 in it now. Can I use the big block engine perches, or will I have to buy some SBC perches. From the pictures I have seen, it looks like the BBC perches are just a few inches higher. Several of the aftermarket perches I see say that they can be used for SBC or BBC. I understand I will have to buy some LS mount plates to mate the motor to the factory motor mounts.
Thanks.
Gregg

ls1nova71 · 05-05-2016, 05:37 PM

I dont really see why you couldn't use the big block mounts, but question why you would want to? With the money 72 only bb mounts bring, you could get some sb mounts and conversion plates and still be money ahead. Just my opinion though.

72MARIO · 05-05-2016, 07:49 PM

I have to look thru my bookmarks to find the link to a suburban build . I know they were not able to use the BB mounts .

1972GMC2500 · 05-05-2016, 10:14 PM

Thanks for the replies. I am probably going to go with the mounts and perches from Early Classic Industries. Has anyone had experience with them? What is special about the 1972 Big Block perches? How much should I be able to sell them for?

05-05-2016, 10:46 AM	#1
1972GMC2500 Registered User Join Date: Aug 2015 Location: Kaufman, TX Posts: 15	Big Block perches 1972 GMC 2500 LS swap I'm trying to get everything ready to transplant a 5.3l LS into my 1972 GMC 2500. It has a 402 in it now. Can I use the big block engine perches, or will I have to buy some SBC perches. From the pictures I have seen, it looks like the BBC perches are just a few inches higher. Several of the aftermarket perches I see say that they can be used for SBC or BBC. I understand I will have to buy some LS mount plates to mate the motor to the factory motor mounts. Thanks. Gregg

05-05-2016, 05:37 PM	#2
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: Big Block perches 1972 GMC 2500 LS swap I dont really see why you couldn't use the big block mounts, but question why you would want to? With the money 72 only bb mounts bring, you could get some sb mounts and conversion plates and still be money ahead. Just my opinion though. __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

05-05-2016, 07:49 PM	#3
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	Re: Big Block perches 1972 GMC 2500 LS swap I have to look thru my bookmarks to find the link to a suburban build . I know they were not able to use the BB mounts . __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

05-05-2016, 10:14 PM	#4
1972GMC2500 Registered User Join Date: Aug 2015 Location: Kaufman, TX Posts: 15	Re: Big Block perches 1972 GMC 2500 LS swap Thanks for the replies. I am probably going to go with the mounts and perches from Early Classic Industries. Has anyone had experience with them? What is special about the 1972 Big Block perches? How much should I be able to sell them for?



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