Good combo, especially for 35" tires.
CK5
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1972 K5 "Boise" Blazer Build (advice appreciated) mostly DIY.
- Thread starter Bernard IV
- Start date
I'm planning on 33s.
That is a lot of gear for 33's
bp71k5
3/4 ton status
Subb’d
Is it too much? Remember I am using a 700r4 overdrive transmission. I spent a lot of time figuring and that is what I came up with. I found some real world advice in this thread and these guys are liking the 4.56 https://www.pirate4x4.com/threads/4-11-vs-4-56-33s-and-700r4.1729570/
Here is the suspension stuff.
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33s and 4.10/4.11 with an overdrive trans is a great combo.
Am running 33s and 4.88. My 65mph rpm is @ 2350. 4th gear effective ratio is 3.42.
4.56 is 3.19. I had 4.1 33s and 700r4 I didn't like it. Maybe if I had a big block I would
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It seems like everyone with real world experience with this combo is saying to go to 4.56 ratio. A 4.30 or around there seems like a good compromise but not sure if they make something like that.
All comes down to what you want more, performance or fuel savings. Think about how you will be driving it most of the time...Freeway or city or dirt. If you're not going to be going 75 on the freeway because you're around town most of the time, there's your answer. But if you're pushing your truck just to cruise at 75 on the freeway, that gets old fast, and with gas prices, expensive, too. I like the choice of sticking with the GM air. I put a Vintage air system in mine, and while it works, it's nowhere near as good as the OEM stuff. Hopefully you'll be able to find your parts, though...Great progress so far!
Seems I have a strange axle seal repair with the seal on the inside.
I got the new axles for 150 each, great deal.
I will have to think about the gearing more this weekend.
I got the new axles for 150 each, great deal.
I will have to think about the gearing more this weekend.
only 122 rpm difference between 4.3 and 4.56 2024 and 2146. Go with the 4.56. First gear 3 x 4.56 x 1.96 give you a crawl ratio of 26.8. That will go over a few things
Here are a few speeds and revs I would be at in overdrive. I checked my 2009 Silverado with a 4L60 series 4 speed and the proposed Blazer gearing is about 350 RPM higher. Not too bad and the truck is a total dog too.
Go 4.56
Martin
Martin
your 33" tires will never be 33" I use 32.5" on average. No we need to discuss Torque converter stall speeds. I asked for a 1600-1800 rpm stall, since my cam is advertised at 1500 to 4000 range. Only my set up doesn't seem to come alive till @ 2700 rpm. My 4th gear locks up as soon as it shifts to 4th. May add a vacuum delay valve to allow a few seconds of torque multiplication to continue in 4th, before locking up.
Without changing anything in the engine or gears If I were to choose a new torque converter stall I think 2000 rpm may be better, I am by no means a torque converter expert, and would like to hear others thoughts on TC stall for our heavy crawling type needs.
Without changing anything in the engine or gears If I were to choose a new torque converter stall I think 2000 rpm may be better, I am by no means a torque converter expert, and would like to hear others thoughts on TC stall for our heavy crawling type needs.
The transmission build order says we have a "2300 to 2500" stall. This will be with a GM crate 383 so it should all hit pretty hard.
I thought about the gears and after going through the Dana 44 the center section looks really good so I've decided to just run with the stock 3.73s for now. If it is bad I can drop the truck off at the 4X4 store and have it changed later pretty easily. I'm a bit nervous about going too low and I'm not 100% sure what we are doing for wheels and tires just yet so I will put the gearing on the back burner for now. If my axle guy doesn't like the rear ring and pinion condition I will probably change it though.
This week I am going to order all new brake stuff at NAPA and put the rear drums back together before I have my guy rebuild the rear axle. I'm ordering bearings for the front spindles and am going to rebuild those. I will also need new front joints for the axles. I have a whole pile of chassis parts sandblasted and ready to go. When the axles are done I am painting everything with the Chassis Saver.
I thought about the gears and after going through the Dana 44 the center section looks really good so I've decided to just run with the stock 3.73s for now. If it is bad I can drop the truck off at the 4X4 store and have it changed later pretty easily. I'm a bit nervous about going too low and I'm not 100% sure what we are doing for wheels and tires just yet so I will put the gearing on the back burner for now. If my axle guy doesn't like the rear ring and pinion condition I will probably change it though.
This week I am going to order all new brake stuff at NAPA and put the rear drums back together before I have my guy rebuild the rear axle. I'm ordering bearings for the front spindles and am going to rebuild those. I will also need new front joints for the axles. I have a whole pile of chassis parts sandblasted and ready to go. When the axles are done I am painting everything with the Chassis Saver.
Real world? Pirate? That's crazy talk! LOL
I put 3/4 ton axles under my 91 with 4.10s, 700r4, Kenda r/t 35x10.50r17.
Speedo reads about 10% over now ( speedo 56/gps50) I am mainly street/hunt club/dirt roads right now. I want to put a tach in to see what's going on, but this feels good. I considered swapping these axles to my suburban (3.73, 295/75/16, th400) that seems slightly under powered. I think the 3.73s would be fine for my current use and should approximate factory final ratio with these tires, but I'm looking to move this truck to Colorado in time to use there. Primarily FS roads and such, not really rock crawling, and I think I'll like the 4.10's better there.
Good idea to run the 3.73s right now and get a feel for how much more you need.
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I'll just see how it goes. I'm expecting issues with the transmission hunting between 3rd and overdrive but maybe it won't.
F'n drum brakes. For sure the most difficult set I've done battle with.
I've spent at least 30 hours sandblasting but am getting to the end of the rusted chassis and axles. The good news is that my frame only had surface rust so no deep pitting or anything like that. I changed my mind on the frame paint and am going with the SPI epoxy black primer. It is a bit of a process but it should be a really tough finish. I have all of the parts to get the Blazer back on its wheels so hopefully I will be there by the middle of May.
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I finally got my frame and axles painted with the SPI epoxy it turned out pretty good. I botched and ran paint in a few spots but that all can be fixed if it sticks out. Lots of work getting it to this point but going forward there won't be any more heavy restoration of rusty old parts as we have a new body. Next up is rebuilding the axles and I still have to build a hitch rear bar setup.
