New Guy Question - What lift for 37" BFGs? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

IGOR · 02-20-2003, 11:08 PM

Please welcome the new guy! - I've been a member of Coloradok5 since almost the beginning - but embarrasingly enough, just found this website - and to my surprise there are a lot of people from Oregon & WA in here - mega-cool!

I have a '72 K5 Blazer that I'm wanting to put 37x12.5x17 BFG Muds on -

Right now I'm putting an ORD shackle flip on the rear - it will be pretty simple to go to 8" at the rear right now with the old 4" blocks I have laying around.

Would 8" springs be sufficient at the front to fit 37s?

Or - I have some 6" Superlift front springs off a '75 Chevy 3/4 ton K20 - would these be enough?

Thanks for your help!

Pont · 02-20-2003, 11:53 PM

IGOR, welcome to the board and nice to see another Oregonian here.

I'm thinking you might get by with 8" springs up front, so long as you don't go any wider than 12.5 on the tire and be careful on how much reverse offset your rims have. I'm running an 8" suspension lift on my 67 with 35x14.5x15 tires and I CAN get the front tires to rub a little. However, these tires are on 14" wide rims with only 3 5/8" backspacing so those meats really hang on there on my truck. Good luck, keep us posted on what you decide to do.

Mike C · 02-21-2003, 10:50 AM

As noted, depends on how aggressively you drive. I want to do 37's on the Jimmy and my plan is to go 6" lift with 10" utilizing 4 1/2" backspacing. I ran 35 14.5 with 4" lift on 10" rims with 3 5/8" BS. Most of my rubbing troubles have been because of a right front fender repair that was done incorrectly. My 35 BFG are taller than my old Mickey T 35's, so I removed a pie piece from the front of the rear quarters about 3/4" at the bottom tapering to zero up about 5" to make the quarter opening mostly round instead of hooked like the stock setup. I may mod my front fenders as well in order to run 37's and NOT use more than 6" lift.

**Yukon Jack** · 02-21-2003, 03:45 PM

Welcome! Got any pics?

IGOR · 02-22-2003, 03:06 PM

No - Unfortunately my CK5 page seems to be down right now...

I will get some up when I get a chance...

cornfed · 02-23-2003, 02:44 AM

Hey Igor with 10" wheels you should be fine with 8" of lift if you leave the factory shackle limiter on the frame. My 72 suburban has 8" springs with 37" ssr's and it occasionally rubs when I take it to sand lake.

IGOR · 02-27-2003, 10:41 PM

What (and where) is the factory shackle limiter? - on the front or rear?

Mike C · 02-28-2003, 03:07 PM

On my Jimmy there is only one. It is on the fram right behind the drivers side spring eye and shackle. It only allows the shackle to go back so far before contacting this stop.

02-20-2003, 11:08 PM	#1
IGOR Registered User Join Date: Feb 2003 Location: Damascus, OR Posts: 260	New Guy Question - What lift for 37" BFGs? Please welcome the new guy! - I've been a member of Coloradok5 since almost the beginning - but embarrasingly enough, just found this website - and to my surprise there are a lot of people from Oregon & WA in here - mega-cool! I have a '72 K5 Blazer that I'm wanting to put 37x12.5x17 BFG Muds on - Right now I'm putting an ORD shackle flip on the rear - it will be pretty simple to go to 8" at the rear right now with the old 4" blocks I have laying around. Would 8" springs be sufficient at the front to fit 37s? Or - I have some 6" Superlift front springs off a '75 Chevy 3/4 ton K20 - would these be enough? Thanks for your help!

02-20-2003, 11:53 PM	#2
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	IGOR, welcome to the board and nice to see another Oregonian here. I'm thinking you might get by with 8" springs up front, so long as you don't go any wider than 12.5 on the tire and be careful on how much reverse offset your rims have. I'm running an 8" suspension lift on my 67 with 35x14.5x15 tires and I CAN get the front tires to rub a little. However, these tires are on 14" wide rims with only 3 5/8" backspacing so those meats really hang on there on my truck. Good luck, keep us posted on what you decide to do. __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

02-21-2003, 10:50 AM	#3
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,728	As noted, depends on how aggressively you drive. I want to do 37's on the Jimmy and my plan is to go 6" lift with 10" utilizing 4 1/2" backspacing. I ran 35 14.5 with 4" lift on 10" rims with 3 5/8" BS. Most of my rubbing troubles have been because of a right front fender repair that was done incorrectly. My 35 BFG are taller than my old Mickey T 35's, so I removed a pie piece from the front of the rear quarters about 3/4" at the bottom tapering to zero up about 5" to make the quarter opening mostly round instead of hooked like the stock setup. I may mod my front fenders as well in order to run 37's and NOT use more than 6" lift. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

02-21-2003, 03:45 PM	#4
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Welcome! Got any pics? __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

02-23-2003, 02:44 AM	#6
cornfed Registered User Join Date: Dec 2002 Location: washougal wa Posts: 38	Hey Igor with 10" wheels you should be fine with 8" of lift if you leave the factory shackle limiter on the frame. My 72 suburban has 8" springs with 37" ssr's and it occasionally rubs when I take it to sand lake. __________________ 68 blazer buggy 68 stepside 58 gmc

02-22-2003, 03:06 PM	#5
IGOR Registered User Join Date: Feb 2003 Location: Damascus, OR Posts: 260	No - Unfortunately my CK5 page seems to be down right now... I will get some up when I get a chance...

02-27-2003, 10:41 PM	#7
IGOR Registered User Join Date: Feb 2003 Location: Damascus, OR Posts: 260	What (and where) is the factory shackle limiter? - on the front or rear?

02-28-2003, 03:07 PM	#8
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,728	On my Jimmy there is only one. It is on the fram right behind the drivers side spring eye and shackle. It only allows the shackle to go back so far before contacting this stop. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax



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