The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Top Speed in a 61

I am restoring my 61 Chevy Apache 1/2 ton and was wondering about its capabilities. Right now it has a 235 I6 connected to a Saginaw 4spd tranny with a granny first gear. I was planning on converting it (if needed) so it would be highway worthy. Now i am pretty sure that this can be accomplished by swapping out a rear end, or the transmission from an S10. Well i was wondering what the stock top speed is to decide if i even need to do this? I also do not want to be revving the engine at very high rpm's the whole time it is on the highway. So what would be the most cost efficient upgrade, if needed at all? Any advice would be much appreciated!

I have a 62 with the four-speed transmission and about 33 inch tires. A couple times a year I take it on 100 mile trip on the highway and I get up to around 60-62 according to the GPS. The engine is a 235 and it winds up around 3000 RPM. I have 455 gears in the rear end, as it is a three-quarter ton. 55 or 60 is really no problem.

Does 55 or 60 stress out the engine more than it should be stressed and decrease its life though?

You know if you can get her geared just right, I hear you can get 80, At least thats the line the cops give you for the ticket

I have the exact same truck, 61 with a 235 and four speed. Mine has 3:90 gearing in the rear end. It'll do 60 miles an hour no problem...actually probably does more than that...I keep up with Calgary highway traffic, which is usually about 110 to 120 Kilometers an hour, which I think is more than 60 miles an hour...

What can i do to be able to comftorably do 65 at 2000rpm's though? I would prefer to keep the 4spd, but can i just put in a new ring and pinion? if so what size? has anyone done this?

We need more data to answer your question: What rear tire diameter will you be running and what is the current rear axle ratio?

Here are a couple threads that you might want to look at:

https://www.stovebolt.com/ubbthread...p;Words=ratio&Search=true#Post769569

https://www.stovebolt.com/ubbthread...p;Words=ratio&Search=true#Post621801

I think that 2000 rpms at 65 mph would be worse for the engine in terms of lugging. I can go 55 - 60 all day in my K20. My first truck was a 66 C10 which I drove 65-75 on a regular basis.

Most cars that I have driven are within 10 percent of 3000 rpms at 60 mph. Try yours a few times and see how it feels. You may decide that you are ok as is.

Dont know about the 4 speed, but my 63 w/230 and 3 speed muncie will do 80-90 if passing, but I try and keep her under 70 due to age