rear axle and driveline upgrades

[norville]

Hello all, I'm picking up a stock 1954 3100, 235 4 speed sm420. I'm looking for any advice or words of thought on the vehicle and the driveline setup..

I plan to drop it with a 4" beam from Sids and a combo of blocks and spring for the rear.. I will be adding front discs and a dual master. I'm still on the fence on whether to go 5 lug or keep the 6 lug..

I'd be running a 27 to 29" rear tire depending on the rear gear ratios.. not really looking to run a V8 , I do want to tool around town and occasional highway driving 20 - 30 miles max..


My first question what is the spring pad width center to center pin ? I know the max width wsm should be 60-62"



I know the engine is not running, but it turns free. The vehicle is not in my possession yet.. That engine may be a runner,but I don't know.. Can I use a 12v battery to do compression checks and try to get it running? before I convert it from 6v

from least to most work..

option #1; get the unknown 235 up and running.. ( I would have trust issues with this option) adding hei, cast header and maybe a bigger carb or cam

2a swap rear to open drive line gears? 3.50?
2b swap in 3.32 gears and keep torque tube.
2c swap in t5 from s10 I'm not made of money so I'll prob have the crappy 4cyl gear set and open rear with 3.75 or 4.10



option #2; I can get a 1958 235 with low miles in running condition of $400 out of a truck.. (would add headers hei, cam ect..)

I have a 4 speed saginaw 2 line here to toss on the rear of it..

2a swap rear to open drive line gears? 3.50?
2b swap in 3.32 gears and keep torque tube.
2c swap in t5 from s10 I'm not made of money so I'll prob have the crappy 4cyl gear set and open rear with 3.75 or 4.10


option #3 I have on a stand a 60k mile running 250 (would add headers cam hei ect..) I have a V8 bell housing here

3a swap rear to open drive line gears? 3.50?
3b swap in 3.32 gears and keep torque tube.
3c swap in t5 from s10 I'm not made of money so I'll prob have the crappy 4cyl gear set and open rear with 3.75 or 4.10


option #4 I can pick up a rebuilt 292 with 4bbl and th400 for $800 then swap rear to open drive line gears? 3.50? not sure if the 292 is worth the extra work to fit with offset mounts or electric fuel pump..



My next question running the numbers is a cruising speed of 2800 (3.75 with 29" tires) OK for the 235 or 250/292 I do live in hilly PA. I thought about going with 3.08 and 27" tires which lowers the rpm for the high gears..2500rpm @ 65

I guess the question should be where in the RPM range do I want the 235 vs 250/292?

I'm reluctant to grab a t5 as most with mechanical speedo are running $500!! and that's with the low first and high OD. If I set my max rpm and mph to that trans the first gear is almost useless .. so why bother it's only a 4 speed and I have one here... I seem to be finding a lot of 3.08's and 3.75 not much in between that will bolt in..


thanks
bob