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| | | | Joined: Feb 2009 Posts: 400 'Bolter | | 'Bolter Joined: Feb 2009 Posts: 400 | Ok! been looking over different pages, trying to decipher the info on the trans I recently received. I do know that it is a New Process, but, having problems figuring out what the preceding numbers should be,435,450, or 465. Cast housing, aluminum rectangle top, twin PTO ports. casting numbers on the case are C-91171,11X3XSPE, and AL, on the top is C-92802, hand brake attached to the case, and band brake on tail output. Any info is appreciated, before I try to stuff this into my '53 2 ton. | | | | | Joined: Mar 2004 Posts: 6,212 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,212 | Here's what I found... It's hard to match up model numbers with casting/part numbers, but I think I figured it out... Case Casting C-91171 is a 1956 only Chevrolet Series 5, 6, 7 & 8 New Process 5-speed (direct drive). That would make it the NP-540 as it holds 10 pints of oil. The 1957 Series 5, 6, 7 & 8 NP 5-speed has case casting number 92116. I ruled out the NP-435 as it only hold 7 pints per my MOTORS Manual and I can't find any Chevrolet NP truck transmissions that hold 7-pints... I also ruled out the 465, as that number SM-465 is a corporate GM 4-speed transmission made in the Muncie Plant from 1968-up. The cover number is a good number used from 1956 at least thru 1967 (exc. TILT). You'll get one additional gear for better puling power, but you won't gain any speed going from the SM-420 to the NP-540. Mike B  | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | 435's have 3 shift rails, 540 series have 4 shift rails, both have Al top covers, 465's have Ci top covers. 540's rarely come with OD gears, however, OD is obtained by using the third gear location, making for a large gap from 2nd to 4th., which is really awkward with a load.
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: Feb 2009 Posts: 400 'Bolter | | 'Bolter Joined: Feb 2009 Posts: 400 | Thanks guys! All information is greatly appreciated! The other number that I saw was NP 4500. Now, I know of the NV4500, and that's why I threw in the NP450 number.
Last edited by PapaJ; 04/27/2020 11:52 PM. Reason: Finished typing
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