Real Top Speed Limit On Stock Tires

About to get a original condition M715 and just curious if 45 mph is a safe speed/rpm limt for bone stock engine/running gear.... or do some of you with stock tornados and axles go a little faster on the highway? thoughts?



Thanks!

It will do dashes of 60 or so. If you want it to live long, keep it at 50 or below. Transfer case heat and seals are the real limiting factor for long high speed runs. That and your hearing.

so most people with stockers just putt around and do off-roading - when you say seals you mean engine seals I assume - right? also is there much of a market for these original engines - mine has 36,500 original miles on it - what woud be a fair price for it if i sold it along with the stock tranny. planning on doing a 350 tbi swap.

No, the engine seals front and rear are either leaking all the time or are ok. The transfer case in most trucks develop a lot of heat. That heat will cause the NP200 seals to leak oil. This will cause your transfer case to loose oil and get hotter. Pretty soon, it will burn up.

If you stay below 50 then you should be able to drive as long as your body can stand it. I have done several 300 mile days in mine at 45-50 mph, but not any more than that.

If you are going to put in a V8, then put serious thought into finding a mid '70's Chevy with a 465 4 speed and married NP205 transmission. You will pay about the same for the transmission/t-case as you will for an adaptor kit to mate the V8 to the stock T-98 transmission.

I put a 396 Big Block in mine with a 2 wheel drive NV4500. I am still running the stock t-case while I collect parts to make the divorced NP205 t-case sitting about 10 feet from me right now work with the stock e-brake and twin stick shift.

To sum up:

Keep it below 50 or change out the t-case. If you want to do a bunch of 50+ driving, think different engine and overdrive.

Yep...in a nutshell, that is it entirely.

And I wouldn't plan on getting much of anything for the stock engine and tranny. Typically they aren't worth what it will cost to ship them so unless you have someone fairly close that wants them, plan on them sitting in the back corner of the garage for a while.

thanks for all the great advice!!!! it's much appreciated!

I'll post my build on here soon for those that are interested.

i drove mine nonstop for 6 hours at 45 mph + and had no problems the first day i had it. that was just to get it home. i have the original 230 tornado.

Have to keep in mind the military typically doesn't convoy very fast. At least not back in the time these trucks were in use.

Always waiting on the treadheads......:lol:

Just kidding Rich!