GT clarification

jaf2021 · 08-29-2012, 11:38 PM

I run a 66 327/275/307 combo in super stock. Can i run a 67 327/275/307 combo and run in GT class or for instance have to claim a 65 327/250/270 or a 65 327/300/285 combo to run in GT class? just a little confusion for me someone please explain
thanks jason

Mike Carr · 08-30-2012, 12:09 AM

jaf2021, many times, the GT rating and traditional (SS/HA, IA, etc) rating are different.

1967 Chevy 327/275, in GT, is rated:
295, OEM head, stick
299, OEM head, auto
300, replacement head, stick
304, replacement head, auto
So be sure to look out for this info when choosing an engine for GT purposes.

As far as an engine for GT, pretty much any motor is fair game, if it is corporately-correct (any Chevy engine in a Chevy, Buick, Olds, Pontiac, Cadilac, etc). Just be sure to use the GT rating when figuring legal Class(es) and weights. Youcould put a 2012 COPO motor in, if you wanted to.

Hope this answers your question.

jaf2021 · 08-30-2012, 01:15 PM

thanks mike i looked at the regular rating 275/307 instead of the gt rating 275/299 for 1967. The motor combo should be the same if i am correct(heads,carb#207). so all i would have to do is change my ss/ia to gt/e-g whichever weight i run. Is this correct?
thanks jason

Mike Carr · 08-30-2012, 03:51 PM

Quote:

Originally Posted by jaf2021

thanks mike i looked at the regular rating 275/307 instead of the gt rating 275/299 for 1967. The motor combo should be the same if i am correct(heads,carb#207). so all i would have to do is change my ss/ia to gt/e-g whichever weight i run. Is this correct?
thanks jason

Yes. Shipping weight of '66 Nova, divided by 299 (or whichever heads/trans you're using) = whatever class. And, you can add or subtract 250 pounds from the shipping weight to adjust classes.

richie 2 · 08-30-2012, 08:52 PM

so it seems that even though a replacement head may be better performance wise, using it taxes you in additional factored hp...therefore more weight?

Mike Carr · 08-30-2012, 10:14 PM

Yes. 5 hp in, say, GT/EA = 5 hp x 10 pound class = 50 more pounds over an OEM head.

trmnatr · 08-31-2012, 12:29 AM

GT/FA weight for a FWD converted to RWD? What is the weight limit, 327, which would be a good model HP to claim

richie 2 · 08-31-2012, 05:03 AM

hey mike, im sniffing at a GT 327ci auto/combo w/small valve an oem head, are the replacement heads for such getting used at all?

Mike Carr · 08-31-2012, 09:32 AM

trmnatr, GT/FA is a 10.50-10.99 pound class (shipping weight divided by NHRA rating of the engine). 10.50 x NHRA rating of the engine + 170 = minimum weight, with driver, across the scales. GT cars may adjust up or down 250 pounds from factory shipping weight. Stockers and traditional (non-GT) S/S care permitted ot run their natural class, up one, or down one. So, whereas, say, a '69 Camaro 427/425 that falls into SS/DA can run CA or EA, GT cars can run, sometimes, up to five different classes (GT/DA EA FA GA) though they may not be able to make the 'top' of the highest of those classes (might have to run 50 pounds heavy for the top of GT/DA) with the 250 pound rule.

Richie2, not sure. Many GT racers are going with later model, lower rated, efi small blocks (80's/90's 305's, etc). Which 327? Some run well with a '64-'66 327/250 combo, like Bob Cupp would run in SS/KA in a '65 Malibu in newer cars. Mike Walter runs well with a 327 like that in a '92 Firebird in GT/IA-JA Maybe he, or someone who runs one can chime in. I'm just a dumb, retired kid (is age 32 still a kid?) who ran FWD Stockers. LOL

Kegracing · 09-10-2012, 04:46 PM

Mike and others:
I have a couple more questions about GT classes. Say my 67 Firebird was an original 6 cylinder car, what shipping weight would I claim if I wanted to run a later model Pontiac 400? What hood can you run in GT?
Also, can you claim a GT motor of the same year as the car? 67 car, with a 67 GT motor combo?
thanks
Ken

08-29-2012, 11:38 PM	#1
jaf2021 Member Join Date: Oct 2004 Location: selmer,tn Posts: 111 Likes: 13 Liked 5 Times in 5 Posts	GT clarification I run a 66 327/275/307 combo in super stock. Can i run a 67 327/275/307 combo and run in GT class or for instance have to claim a 65 327/250/270 or a 65 327/300/285 combo to run in GT class? just a little confusion for me someone please explain thanks jason

08-30-2012, 01:15 PM	#3
jaf2021 Member Join Date: Oct 2004 Location: selmer,tn Posts: 111 Likes: 13 Liked 5 Times in 5 Posts	Re: GT clarification thanks mike i looked at the regular rating 275/307 instead of the gt rating 275/299 for 1967. The motor combo should be the same if i am correct(heads,carb#207). so all i would have to do is change my ss/ia to gt/e-g whichever weight i run. Is this correct? thanks jason

08-30-2012, 08:52 PM	#5
richie 2 Senior Member Join Date: Feb 2009 Posts: 967 Likes: 419 Liked 200 Times in 91 Posts	Re: GT clarification so it seems that even though a replacement head may be better performance wise, using it taxes you in additional factored hp...therefore more weight?

08-30-2012, 10:14 PM	#6
Mike Carr VIP Member Join Date: Nov 2001 Location: Enon Valley PA Posts: 1,650 Likes: 234 Liked 83 Times in 37 Posts	Re: GT clarification Yes. 5 hp in, say, GT/EA = 5 hp x 10 pound class = 50 more pounds over an OEM head. __________________ Mike Carr, Tri-State S/SS Association President Looking for 2015 S/SS Race Sponsors Contact me if interested buffdaddy_1302@hotmail.com (724) 510-5912

08-31-2012, 12:29 AM	#7
trmnatr Member Join Date: Oct 2008 Posts: 168 Likes: 0 Liked 1 Time in 1 Post	Re: GT clarification GT/FA weight for a FWD converted to RWD? What is the weight limit, 327, which would be a good model HP to claim

08-30-2012, 12:09 AM	#2
Mike Carr VIP Member Join Date: Nov 2001 Location: Enon Valley PA Posts: 1,650 Likes: 234 Liked 83 Times in 37 Posts	Re: GT clarification jaf2021, many times, the GT rating and traditional (SS/HA, IA, etc) rating are different. 1967 Chevy 327/275, in GT, is rated: 295, OEM head, stick 299, OEM head, auto 300, replacement head, stick 304, replacement head, auto So be sure to look out for this info when choosing an engine for GT purposes. As far as an engine for GT, pretty much any motor is fair game, if it is corporately-correct (any Chevy engine in a Chevy, Buick, Olds, Pontiac, Cadilac, etc). Just be sure to use the GT rating when figuring legal Class(es) and weights. Youcould put a 2012 COPO motor in, if you wanted to. Hope this answers your question. __________________ Mike Carr, Tri-State S/SS Association President Looking for 2015 S/SS Race Sponsors Contact me if interested buffdaddy_1302@hotmail.com (724) 510-5912

08-31-2012, 05:03 AM	#8
richie 2 Senior Member Join Date: Feb 2009 Posts: 967 Likes: 419 Liked 200 Times in 91 Posts	Re: GT clarification hey mike, im sniffing at a GT 327ci auto/combo w/small valve an oem head, are the replacement heads for such getting used at all?

08-31-2012, 09:32 AM	#9
Mike Carr VIP Member Join Date: Nov 2001 Location: Enon Valley PA Posts: 1,650 Likes: 234 Liked 83 Times in 37 Posts	Re: GT clarification trmnatr, GT/FA is a 10.50-10.99 pound class (shipping weight divided by NHRA rating of the engine). 10.50 x NHRA rating of the engine + 170 = minimum weight, with driver, across the scales. GT cars may adjust up or down 250 pounds from factory shipping weight. Stockers and traditional (non-GT) S/S care permitted ot run their natural class, up one, or down one. So, whereas, say, a '69 Camaro 427/425 that falls into SS/DA can run CA or EA, GT cars can run, sometimes, up to five different classes (GT/DA EA FA GA) though they may not be able to make the 'top' of the highest of those classes (might have to run 50 pounds heavy for the top of GT/DA) with the 250 pound rule. Richie2, not sure. Many GT racers are going with later model, lower rated, efi small blocks (80's/90's 305's, etc). Which 327? Some run well with a '64-'66 327/250 combo, like Bob Cupp would run in SS/KA in a '65 Malibu in newer cars. Mike Walter runs well with a 327 like that in a '92 Firebird in GT/IA-JA Maybe he, or someone who runs one can chime in. I'm just a dumb, retired kid (is age 32 still a kid?) who ran FWD Stockers. LOL __________________ Mike Carr, Tri-State S/SS Association President Looking for 2015 S/SS Race Sponsors Contact me if interested buffdaddy_1302@hotmail.com (724) 510-5912

09-10-2012, 04:46 PM	#10
Kegracing Member Join Date: Jun 2002 Location: Red Oak, TX Posts: 441 Likes: 0 Liked 0 Times in 0 Posts	Re: GT clarification Mike and others: I have a couple more questions about GT classes. Say my 67 Firebird was an original 6 cylinder car, what shipping weight would I claim if I wanted to run a later model Pontiac 400? What hood can you run in GT? Also, can you claim a GT motor of the same year as the car? 67 car, with a 67 GT motor combo? thanks Ken Last edited by Kegracing; 09-10-2012 at 04:47 PM. Reason: cant spell :)