The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Top end speed for my 61 Apache 10

Stock rear end engine changed to a 327 ? No tach so just want to check. Only taken it to 55 mph no problem and sounds good.

Gearing and tire size will dictate top end, as will engine operating rpm.

You will need a better idea of what your axle ratio. With out a tach you won't be able verify how close your "327?" ratio is. I've seen 3.30, 3.42, 3.55 ratios mentioned quite often. You will need to know what your tire size is by diameter. Then you can use an RPM calculator to determine RPM;

http://www.csgnetwork.com/multirpmcalc.html

I don't run a 235, so I'll leave it to others to say what RPM you should run at.

Larry

I think he means it has a 327 engine in it.

yes I do mean a 327 engine with a stock rear end. 3 on the tree and I'll post tire size tomorrow.Thanks

We'll still need the gear ratio, as there were options. Can you get the codes off the axle? Stock rearend for a '61 1/2 ton would be either 3.90 or 4.11. Code should be stamped on the right side of the 3rd member face.

you aint gonna go too fast with that setup unless you have 40 inch tires! 55 tops.......watch the gas guage as you go faster

I wouldn't say that. I have a '55 with a 235, 3.90 gears, and 30 inch tires. I've had it past 70 mph no problem. I drive off the tach, so speedometer error is not an issue.

OK ,tires are 31x10.5 on 15 inch rims.Now where are we ? Thanks for all the brain cells thinking about this !

Assuming the base model 3.90 gears, and a theoretical 5500 redline, along with 31" tires, about 130 mph. That is not taking into account frictional losses, weight of the vehicle, and vehicle aerodynamics.

Looks like there were only (2) rear ratio's for a stock 1960 C10: 3.90 or 3.38

http://public.bay.livefilestore.com...iCNr-eTGE8mWIkF1PmNQ/Truck%20Axle_ID.jpg

Assuming your 327 can handle a cruising rpm of 2600, and a max RPM of 5500:

Trans Ratio = 1

Rear Tire Diameter = 31 inches

Assume a 3.9 Rear Ratio
@ 2600 RPM = 62 MPH
@ 5500 RPM = 130 MPH

Assume a 3.38 Rear Ratto
@ 2600 RPM = 71 MPH
@ 5500 RPM = 150 MPH

thank you that's what I needed

Speedometer would stick if you got over 70. But in 87 I drove mine to Odessa Tx. some cars and trucks passed me and I tried to keep up but it couldn't. I slowed down, about a mile down the road every one was pulled over. I drove right on by glad it wouldn't go that fast.

I don't think I'll be getting any speeding tickets ! Your '61 looks great,do your doors stick out or do you have a magic fix?

My '60, with stock 3.90 gears and a 235 engine will cruz all day at 65, although I keep it at 55 to 60. I did go 70 once. You should do fine.

Somehow I doubt with either gear ratio its going to reach much past 100 mph with a stock 327. It takes a lot of power to push a big box like a '61 Apache through the air...