Swaping 4 speed to auto
 

What is the difference are there between a manual engine and a auto engine.I have a 250bolted to a TH350 bolted to NP205.Which I would like to put in place of my 292 with 4 speed and NP205.Can I just swap engines or can an auto engine be used as manual engine ? without changing a lot of stuff?

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1970 K-10 292 Longbed stepside powersteering but manual brakes!Factory step bumper,Deluxe gauges no Tach 4 speed manual 1 out of 464 made with protectoplate intact.Its basic for a farm truck

all engines bellhousing bolt patternm is same, only manual transmissions use a removeable bellhousing like manual trannies do, i a 4x4 going from manual to auto tranny is a huge ordeal, you will need auto to 205 adaptor, probably different driveshafts if the lengths of thr trannies differ and a flexplate and auto trans radiator and cooling lines of course and linkage and column, and so forth, you will be basically tearing whole truck apart cept axles and engine, this same question has been asked over and over lately, is getting old.
if you search between this page and a few pages back youll find a few threads regarding this

good luck

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Randy- Lincoln, IL
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[This message has been edited by Fast68Chevy (edited May 04, 2002).]

Engines same...carb differences are vacuum for auto tranny, linkages to trannies different. Measure length from back of engine to back of trans/case to see if driveshaft lengths are same (should be with yours). Also may have to run aftermarket tranny cooler if using manual radiator. Tried to post this once, don't know where it went...cyberspace I guess, so if two posts turn up don't think I've got alzheimers..(Even though I probably do). Easy swap! Gary

I swapped a 3-speed manual/NP205 out and put a Th350/NP205 in its place. Other than being VERY heavy the swap is straight forward.

To the best of my knowledge ALL 4wd driveshafts in 67-72 trucks with an NP205 are the same length. The adapter between the tranny and 205 made up the difference in length. I did the swap behind a 350. I can't believe GM made different driveshaft lengths for 6 cylinder engines.

If I was going TO a th350 (and I did) I would take the tranny/transfer apart, put new seals in the adapter, and look at the drive sleeve. If the sleeve is worn or has grooves from the oil seals now is the time to replace it. The seal between the sleeve and front of the adapter keeps ATF in the tranny. The back seal keeps the 90 weight in the NP205. You don't want to mix them.

The NP205 from a auto has a different input shaft than the manual one. If you have a th350/np205 already together you don't have to worry about swapping input shafts.

You will then need an auto column and the th350 shifter linkage. This stuff SHOULD be the same between 2wd and 4wd. My linkage came out of a 4x4 but looks like stuff I've seen in 2wd trucks.

If you want part numbers for the stuff I bought I have them squirreled away at home. Drop me an email if you are interested.

The beauty of the swap is I have all the parts out of my parts truck ,only difference being going from a 72 shorbox to a 70 long box both being 4x4's. I m hoping my drive shaft will work or will have the old short box shaft rebuilt to work.After I master this I will make the swap to power disc brakes later this summer,all coming from my parts truck.

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1970 K-10 292 Longbed stepside powersteering but manual brakes!Factory step bumper,Deluxe gauges no Tach 4 speed manual 1 out of 464 made with protectoplate intact.Its basic for a farm truck