The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - New Blazer 1972 - Got Questions ;-)

**Yukon Jack** · 10-17-2008, 09:38 AM

I'll give you a little of my thoughts on 35"s. My first lift on my 69 K20 was a 4" Tuff Country lift with a shackle flip out back. I got 35x12.50x16 Super Swamper SSR's on 16x8" rims with 4.5" backspacing. This truck has 4.56 gears with an SM465 (4 speed manual). I never had this truck crossed up so I can't speak to whether it would have had tire rub, but I would guess it would have. On the street I had absolutely no rubbing. Gear ratio-wise, the highway rpm's are pretty high going 55-60 mph.

I put a 4" lift on my 70 K5 consisting of 4" Superlift front springs and at the same time I swapped in 3/4 ton running gear with 4.10 gears. For the rear lift I had to modify the rear spring perches anyway so I'm using a 2" block and custom spring perches that level out the K5. While I've had my 69 torn apart I put the above 35" Super Swampers on my K5. For whatever reason, these tires on the K5 do rub on the steering components when turning one direction and they are much closer to sheetmetal than when they were on the 69 K20 with a 4" lift. That obviously means the 4" lifts aren't actually the same size so keep that in mind when you buy a lift kit - just because it says it's a 4" lift, that doesn't mean that is what you will end up with. I really like the 35"s with the 4.10 gear ratio - highway speeds are noticeably more rpm friendly. The engine doesn't seem to mind the gear ratio either powerwise.

In the end, I think I would highly recommend a 6" lift with 35"s. I think either 4.10 or 4.56 gear ratio will be a good pick, just really depends on what your going to want to do.

6" lift on a K5 will probably require driveshaft mods, but again, you just don't know for sure until you get into it. I guess your doing Dana 60's anyway so driveshaft mods are probably on the table anyway.

You have a great looking K5 and I hope you'll find this board to be a great asset.

I sometimes find the search function to work really well for what I'm looking for, but other times it can be next to worthless.

Keep us updated on your project's progress.

10-17-2008, 09:38 AM	#20
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,689	Re: New Blazer 1972 - Got Questions ;-) I'll give you a little of my thoughts on 35"s. My first lift on my 69 K20 was a 4" Tuff Country lift with a shackle flip out back. I got 35x12.50x16 Super Swamper SSR's on 16x8" rims with 4.5" backspacing. This truck has 4.56 gears with an SM465 (4 speed manual). I never had this truck crossed up so I can't speak to whether it would have had tire rub, but I would guess it would have. On the street I had absolutely no rubbing. Gear ratio-wise, the highway rpm's are pretty high going 55-60 mph. I put a 4" lift on my 70 K5 consisting of 4" Superlift front springs and at the same time I swapped in 3/4 ton running gear with 4.10 gears. For the rear lift I had to modify the rear spring perches anyway so I'm using a 2" block and custom spring perches that level out the K5. While I've had my 69 torn apart I put the above 35" Super Swampers on my K5. For whatever reason, these tires on the K5 do rub on the steering components when turning one direction and they are much closer to sheetmetal than when they were on the 69 K20 with a 4" lift. That obviously means the 4" lifts aren't actually the same size so keep that in mind when you buy a lift kit - just because it says it's a 4" lift, that doesn't mean that is what you will end up with. I really like the 35"s with the 4.10 gear ratio - highway speeds are noticeably more rpm friendly. The engine doesn't seem to mind the gear ratio either powerwise. In the end, I think I would highly recommend a 6" lift with 35"s. I think either 4.10 or 4.56 gear ratio will be a good pick, just really depends on what your going to want to do. 6" lift on a K5 will probably require driveshaft mods, but again, you just don't know for sure until you get into it. I guess your doing Dana 60's anyway so driveshaft mods are probably on the table anyway. You have a great looking K5 and I hope you'll find this board to be a great asset. I sometimes find the search function to work really well for what I'm looking for, but other times it can be next to worthless. Keep us updated on your project's progress. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14 Last edited by Yukon Jack; 10-17-2008 at 09:41 AM.