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New 72 Blazer... Questions on upgrades.

T

Tschmidt1

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I just picked this beauty up in Dallas and shipped it up here to Seattle. All the big, expensive things have been completed (454 complete rebuild out of 71 chevelle SS, tranny, transfer case, candy paint, upholstery). I have a few questions...

The first is with axles and gears. It currently has d44 & 12 bolt rear with 3.07 gears. It is running 37' toyos. I spoke with someone at Randys R&P and was told since this will be mainly a pavement princess ( due to the paint job) with occasional towing needs, upgrading the axles and diff covers, and gears should be adequate. If I went chromoly axles in front with the alloy axles in the rear, would I be happy with this setup rather than going dana60/14bolt route?

The second question is has anyone used these rigs as a good tow vehicle? I understand the short wheel base, yada yada yada, but with rear disc conversion, upgrades to suspension, and a custom hitch, would anyone here feel comfortable towing 6500LBs with one of these rigs? my boat is 28ft long 4500Lb dry weight 6500 with trailer fully loaded. I am in Seattle so this would be once per week to the lake for 3 months with 1-2 trips per year over a pass. Any recommendations on upgrades in order to accomplish this? I know I have more than enough power, and I know I will need to do some sort of axle/gear swap along with disc brakes in the rear. Any advice would be awesome !

Lastly what experience do people have with the dakota digital gauges in terms of installation? I think they would tie in nice with the blue paint
 

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First off what trans and t-case is in the rig? If this is mainly a pavement pounder I would not be worrying about buying aftermarket alloy axles but I would be changing gears since you plan to tow with it but what ratio depends on which trans you have and also if you plan on staying with the 37" tires or going bigger/smaller.
 
Here are the specs:


Freshly completely built 454 (450-500hp)

Fresh Turbo 400 transmission built for this motor

Fresh np205 transfer case
 
I'd go 4.10 gears if you plan on staying with the 37 s. the 454 should have more than enough power to push those gears. It will be night and day from the 3.08 gesrs in it now. I've towed close to 5 thousand with my 72 and it did good. The 12 bolt I've found is a weak link. I've broken 3 and that's with 35s. Two were offroad and a third snapped the carrier on dry pavement. Maybe with stronger gears a shafts it will do better than mine did. Keep an eye on the small bearings in the front hubs. I kept blowing those out until I upgraded to the bigger bearing later model 3/4 ton fronts.also ball joints wear faster with the big tires. Good luck and welcome to the firsts gen blazer club.
 
In my opinion that boat is too much weight for your blazer. Then add a lift and 37's and your asking for trouble in my opinion.
 
How does it drive now?

Normally 3.07s would be doggy as hell, but with that much torque it may work OK on the street..... And highway RPMs would be nice and low.

The only concern would be transmission temps. Those lousy gears put a lot of extra heat into the transmission, so you should get a gauge on it to see how much you are cooking it.

The problem with swapping gears will be the loss of good highway RPMs. Without an OD transmission, you are going to be spinning a lot more revs once you put correct gears in the axles.... What speed do you normally like to drive on the highway?

-G
 
Surprisingly its not a dawg with the current setup, but if towing I'll want lower gears. Has anyone tried using a weight distribution setup for a better towing capability on one of these? My hope is between axles, gears, and disc brakes in the rear along with air bags that it will get the job done.

I attached pictures.

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Legally you'd be in trouble towing that boat. A blazer doesn't have that high of a gvwr rating. I'm not sure the exact number. But I remember it being somewhere in the 5500 range max. When I towed my other blazer home I didn't go over 45. Your boat is much heavier and if something happened you'd be liable. With thàt in mind you may not have any problems towing that much, but your axles are not rated to carry that much weight, with or without the alloy shafts. The bearing take the load if the truck on 12 bolts and will put a lot of stress on the ring gear pulling the boat. A full floater 14 BOlt will take the weight and with the extra pinion bearing the deflection from the ring gear will be less. Just a few things to think about. The front end won't matter as much because you won't be using it as a drive axle most of the time.
 
Looks like you've got some work to do on those bumpers....

The body lift is putting those bumpers WAY out of position from where they are supposed to be. Looks like a 3" body lift from the pics. (?). :dunno:

-G
 
Unless you are going to be in deep sand or mud pulling that boat to water, I would go down a size or so in tires.
37s are nice for offroad, and can run on the highway good, but trying to tow that much with them is not good.
It puts your center of gravity up higher, really loads down the brakes and puts more strain on the drivetrain.

12.50/33s, or slightly smaller will make a world of difference for towing. They might not look as good on the truck, but the truck will look a heck of a lot better with them on upright, then it will look with the 37s on and flipped.

A load leveling hitch, properly setup, will help take the load off the rear axles, which is a good thing.

Make darn sure that the trailer brakes are working and maintain them well. In an emergency, they are what will save your butt.

Mechanical surge brakes are great, and properly setup, you cannot even tell the boat is back there when you go to stop.
But, electric brakes will stop a sway situation. If a big truck passes you, or you hit a crosswind and the trailer starts swaying, you hit the gas and the trailer brakes at the same time with the actuator.

It will snatch it back straight in a second. Same for going down a steep hill.

Just let the truck roll, and use the trailer brakes to slow you down. No danger of jackknifing.

Oh, and if that Turbo400 has stock cooling, I would add a big cooler. And definitely go with synthetic in the 205 and rear end.

Switching from standard 75W90 to the same in Amsoil knocked about 100 degrees off the case temp of my 205 when running down the highway.

It went from too hot to touch with heat coming up through the floor, to touchable just by changing to synthetic.
 
It's my understanding they had to do the body lift to accommodate the 454. What is the best route to go to correct the bumpers? I have been told to get the bumpers fabricated to bring them up higher, or do some sort of sheet metal fabrication to cover the gap. Any thoughts?

Thanks for the advice. Anyone know where to find rear hatch hardware for a hardtop?
 
Tschmidt1 said:
It's my understanding they had to do the body lift to accommodate the 454. What is the best route to go to correct the bumpers? I have been told to get the bumpers fabricated to bring them up higher, or do some sort of sheet metal fabrication to cover the gap. Any thoughts?

Thanks for the advice. Anyone know where to find rear hatch hardware for a hardtop?
Click to expand...

Its not that hard to have some offset brackets built to move the bumpers up 3".... That's the best way to do it IMHO. Trying to fill in the gap with sheetmetal would still look terrible.

You'll need to trim the frame horns a bit to get the bumpers to tuck in correctly at the new height. It will make sense when you start fitting things together.

Save the "cutoffs" in case you ever want to put the frame back to stock again.


-G
 
Not much hatch hardware to be had. I'm looking for new handle and connecting rods in mine and no one makes repro ones.
 
Bummer my hatch won't stay latched now was just getting ready to post a thread asking about hardware.
 
Since you are a paying member, you can post in the wanted forum. The latches on the top are adjustable where they hook the post on the top. I would take them out and clean and lube the latch mechanism. Helped mine ßtay closed better.
 
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