NP 440 swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dieseltech619 · 03-10-2014, 10:13 AM

I have done a lot of searching on this subject and there doesn't seem to be a ton of info and what i have found all seems to be different in one way or another so i still have a few questions which i think i know the answers to but would rather not have any surprises. I scored a complete gm unit this weekend bell housing trans and shifter. The swap looks pretty straight forward, my truck is 3 on the tree with a bell housing mount not a rear trans mount and the np440 bell doesn't have a provision for a mount.
1st. i need to install an automatic trans style cross member and mount right?
2nd. will the factory clutch linkage work or will i need to modify it in anyway?
3rd. will i need a high hump trans tunnel?
4th. How well does the overdrive perform? How much of an increase in fuel economy did you see? and also what engine and rear gearing are you using?
5th. The trans also came with the flywheel and used clutch, PO converted to automatic so his wife could drive the truck also, Will i be able to use the flywheel my 307 already has and i believe the trans calls for an 11" 10 spline clutch i should just be able to use a factory replacement for a 81-87 c-10 that was originally equipped with the trans right?

mixermike · 03-10-2014, 07:02 PM

I just finished this swap.i can't answer all your questions but I wil answer what I can. I have a 63 with a 283, 3 OTT, 373 rearend gears. I found a trans with the chevy bell housing bolt pattern. I have bell housing mounts so I didn't have to worry about a trans crossmember . I had to have the bearing retainer turned down so it would fit in my stock bell housing. I used my stock clutch pressure plate and throw out bearing.you don't need a high hump tunnel.when the trans is in 2nd and 4thh it is right up against the seat, but works ok. I put a little heat to the shifter and bent it closer to the dash because my wife is kinda short and I knew if she moved the seat up it might be a problem getting it in those gears. I am very happy with this trans, it shifts smooth and the overdrive is SWEEEEET. 65mph is about 2000rpm.hope this helps

dieseltech619 · 03-11-2014, 10:49 AM

awesome thanks

03-10-2014, 10:13 AM	#1
dieseltech619 Registered User Join Date: Jan 2013 Location: wilmington Posts: 63	NP 440 swap I have done a lot of searching on this subject and there doesn't seem to be a ton of info and what i have found all seems to be different in one way or another so i still have a few questions which i think i know the answers to but would rather not have any surprises. I scored a complete gm unit this weekend bell housing trans and shifter. The swap looks pretty straight forward, my truck is 3 on the tree with a bell housing mount not a rear trans mount and the np440 bell doesn't have a provision for a mount. 1st. i need to install an automatic trans style cross member and mount right? 2nd. will the factory clutch linkage work or will i need to modify it in anyway? 3rd. will i need a high hump trans tunnel? 4th. How well does the overdrive perform? How much of an increase in fuel economy did you see? and also what engine and rear gearing are you using? 5th. The trans also came with the flywheel and used clutch, PO converted to automatic so his wife could drive the truck also, Will i be able to use the flywheel my 307 already has and i believe the trans calls for an 11" 10 spline clutch i should just be able to use a factory replacement for a 81-87 c-10 that was originally equipped with the trans right? Last edited by dieseltech619; 03-10-2014 at 10:22 AM.

03-10-2014, 07:02 PM	#2
mixermike Registered User Join Date: Jan 2008 Location: Post Falls, Idaho Posts: 606	Re: NP 440 swap I just finished this swap.i can't answer all your questions but I wil answer what I can. I have a 63 with a 283, 3 OTT, 373 rearend gears. I found a trans with the chevy bell housing bolt pattern. I have bell housing mounts so I didn't have to worry about a trans crossmember . I had to have the bearing retainer turned down so it would fit in my stock bell housing. I used my stock clutch pressure plate and throw out bearing.you don't need a high hump tunnel.when the trans is in 2nd and 4thh it is right up against the seat, but works ok. I put a little heat to the shifter and bent it closer to the dash because my wife is kinda short and I knew if she moved the seat up it might be a problem getting it in those gears. I am very happy with this trans, it shifts smooth and the overdrive is SWEEEEET. 65mph is about 2000rpm.hope this helps

03-11-2014, 10:49 AM	#3
dieseltech619 Registered User Join Date: Jan 2013 Location: wilmington Posts: 63	Re: NP 440 swap awesome thanks



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