New to the forum,question on 91 grill update

[tuscani]

I'm sure this question has already been answered but I can't find the answer in the search. I want to put the 91 gmc grill on my 88 suburban. I've noticed that the core supports for the quad headlight system say except 7.4L or 454.
Does anyone know why this is and has anyone done the conversion on a Big Block truck? If so , which core support did you use? Do I have to find a used 91 core support out of a Big Block Truck? Has anyone put one of the Kits that the truck supplier houses sell? Thanks for the info

[Sailor77]

Good question. I don't have a 454 but I do have the 454 radiator and what to do this conversion. Some one has got to know

[CT-Truckster]

if I had my guess I would say it says "except 7.4L or 454" Because i think the 1 ton trucks or something carried the old bodystyle also until 91 and utulized a two headlamp setup, so being that only the 1/2 ton burbs and blazers(maybe others, not sure) carried the new quad headlight setup i'm guessing you couldn't get a 89-91 1/2 ton burb or blazer with a 454?(or anything that had the new quadlamp grill setup). basically i think what the exception means is that if your 89-91 truck has a 454 then it is going to use the dual headlight setup, so the quadlamp rad. support won't accept the dual lamp grille setup. but anyway to answer your question about the 91 quadlamp rad. support it will work just fine with your bigblock 88 suburban. for the quadheadlamp design you need a quadlamp rad core support for a 89-91 1/2 ton suburban and it will bolt right up no matter what type or size engine you have, radiator and all, of course you will need all the grill parts and lamps and such. I hope that makes sense, i'm allready confused just reading it back to myself. maybe someone will straighten me out if I'm wrong.

[gchemist]

The conversion is a piece of cake. :hit2:
I also run a 454 aluminum 4 core radiator. No cooling problems, especially with dual 14" fans too.

[SanitysBane]

I put in a HD radiator (454) in place of the stock 305 radiator. It just bolted right in.

[Sailor77]

I just got any entire support, lights and grille this weekend. I have an entire extra wiring harness in good condition should anyone need. Also have a second set of lights and brackets.
I am hoping to find someone to sandblasdt the support so I can paint it before installing. BTW, who make a billet grille for the GMC version?

[tuscani]

That's what I love about these forums. Everyone is ready to help someone with questions. Don't know if I can return the favor but I run a Automotive Parts Warehouse in So California and if anyone has a question about truck parts I may be able to help.