383 Stroker, TH350, NP205, D60/14BFF w/ 4.56's - best tire size?

[6872xtc]

I think that you will like the 37's.
I would have a good cooler to help the trans out as much as possible though.
And if you ever decide to go to a 700R4, I highly recommend the TV made E-Z kit from Bowtie Overdrives. It made a huge difference in my opinion, completely different, and better.
I can't tell you about their transmissions, but they have the TV system dialed in.

 

[chulisohombre]

With your setup I'd go 38s and trim a bit. The rolling height will help with highway rpm and still have decent power off-road.

 

[6872xtc]

I forgot to add, if you are going with Alcan springs, you could have them move the axle forward an inch to keep the surgery less intense. At least I would rather work on the front of the fender than the bottom of the cab /firewall.
Just my 2 pesos. ...

 

[handloader90]

I had an A-Bomb on my '79 K5 and was running 52's up front (I never finished that project though). I would like to have a centered pin vs. an offset on, was thinking of having them make some 49" or 50" springs so I can move the axle forward a little bit.

I'm just gonna keep the highway speeds at 55 M.P.H. which is what the speed is out here instead of getting way up in the R.PM.'s.

 

[6.2Blazer]

How does overdrive work? Does it kick in at a certain R.P.M. or speed?

It's just like having another gear in the transmission......instead of shifting through 3 gears it shifts through 4. The OD gear ratio of a TH700R4 is 0.70:1 as compared to the typical non-OD top gear of 1:1. With 4.56 axle gears, if you had the OD transmission and it was running in OD/4th gear it would be equivalent in engine RPM as if you only had 3.20 axle gears in a non-OD equipped rig. The other advantage to the 700r4 is the 1st gear is lower also.

 

[handloader90]

So at some point it will be worth looking at getting another 7004r. What about that pigtail that comes out of the 700r4? How do you wire that up to a rig not originally equipped with that technology?

 

[454Sub]

All it really needs is the converter lockup. Which is controlled through the brake switch.

 

[6872xtc]

The torque convertor lock up needs power and ground, but most have the ground supplied inside the trans case.

There are kits that will help, the B&M one has speed adjustability. That can be helpful since it is possible to lock the convertor starting with 2nd gear. I have a toggle switch on mine.

 

[Hoss7979]

36-37" tires are gonna be right in the spot between good mpg & DD.