[Alex V.]

The theoretical top speed of my '85 1-ton with TH400 and 4.10's, just by engine redline+gear ratios, etc., is 110. Being a 454 it might have the power to hit that, but on our trucks in stock form the engine will usually just come to the limit of its air supply or the valve train will reach its limit (valve float) before the technical redline. With especially high gears like your 2.73's the wind resistance may dictate, basically, "terminal velocity" just because the engine doesn't have the power to push it any faster, before it hits redline or valve float territory.

I've had my '85 to 85 once - I still had plenty more throttle but just didn't keep going. I believe it could hit 100 but that's a lot of big components spinning real fast so I'd want to know it's all in real good shape before trying.