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| | | | Joined: Jan 2016 Posts: 6 New Guy | | New Guy Joined: Jan 2016 Posts: 6 | My 48 Loadmaster has a newer 235 (1960) and it runs great, will cruse at 45-50 mph no problem, it has a 2 speed rear, 6.13 high-8.10 low, would like to get another 10 or maybe 15 mph out of it by changing transmissions if possible. Would prefer a bolt in operation. Also want to consider an automatic trans, that would handle a 12000-14000 lb. load. My plan is to take the grain box off,and build a tiny house on it. Help ! and Thanks. | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | You could look for a NP-4500 or a ZF 5 speed, that would handle the load. Any OD trans would work to increase speed.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | Your brakes will not stop your truck carrying a 14k load doing 60 mph. I hope upgrading the brake system is in your plan as well. Making them go fast is easy, it's getting them to stop thats the problem... Be safe, Mike B  | | | | | Joined: Jan 2016 Posts: 6 New Guy | | New Guy Joined: Jan 2016 Posts: 6 | yes brakes will be upgraded ! | | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | If your plans include newer style brakes it might be cheaper to find a modern rear with better hwy gears and brakes all as one package...just a thought. Mike B | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | Or you could keep the drive line as original and add an overdrive box. An easy fix if you could find one.
A lot more work could get you a 700R4 like I put into the 48 2 ton. | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | 12-14k load is maxed out or overloaded. The truck is rated for 16 and weighs 4K or a little more. The 235 is a good engine but not overly powerful.
Therefore not much need for faster gears, you'll never use them... Unless being foolish on a downhill.
I estimate the slow gears you have will be necessary.
Be sure brakes are in excellent shape, may consider a dual circuit master cylinder but otherwise original should be just fine. Try to keep total weight under 16k | | | | | Joined: Jan 2016 Posts: 6 New Guy | | New Guy Joined: Jan 2016 Posts: 6 | If I keep the total weight at 14K will a 700R4 hold up ? | | | | | Joined: Dec 2015 Posts: 7 New Guy | | New Guy Joined: Dec 2015 Posts: 7 | The 700r4 will handle that kind of weight just fine. Use a large cooler, stay out of OD except for long flat roads and I would recommend a beefier 3-4 clutch pack kit. It sounds heavy but realize the rearend is geared twice as low as most 3/4 tons. So that takes a lot of stress of the power train.
I slammed a 6.2 Diesel and 700r4 Into a 54 GMC M211 Deuce. It had banjo 6.17 axles too. Do use a later 700r4, fewer issues. I believe mine was from a 1991 s10. | | | | | Joined: Nov 2010 Posts: 1,159 Shop Shark | | Shop Shark Joined: Nov 2010 Posts: 1,159 | Tom,Sorry,but all I saw was a Chevy 4400. Nice truck,B.T.W...But now you have my mouth watering! Please link pics to your M211!! | | |
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