NAPCOs with Automatic Transmissions?

[tristan]

I noticed that the Wikipedia entry for NAPCO says that some NAPCO-converted trucks had automatic transmissions. I've not been able to confirm this anywhere and wondered if anyone here had any insights or opinions?

[nvrdone]

don't believe everything you read on wikipedia

[undertaker72]

my father had a 56 gmc , straight 6 , hydromatic trans column shift, it had no park detent , had to use e brack and it was bone stock factory napco , its long gone , by now it was a short stepside wrap around cab , I wish it and my father were still here , I will attest they were out there

[OrrieG]

With the divorced transfer case would have been doable. Some one smarter than me can chime in and say for the sm460 and Hydro auto were the same length and output spine configuration.

[bajabob]

Tristan
Check with Omar. He has built some beautiful trucks and I am sure he would be able to give you the 411.

Lugo Parts Restoration, Inc.
3329 Swetzer Rd.
Loomis, CA. 95650
www.lugoparts.com
p(916)652-0840

[franken]

Originally Posted by nvrdone

don't believe everything you read on wikipedia

Might want to read what it says here: http://www.napco4x4.org/history.htm

"Apparently NAPCO reached an agreement with both GMC and Chevrolet to supply them with the Powr-Pak conversion kits, and GMC began to produce 4x4 trucks on the factory assembly line (using NAPCO components) starting in 1956, with Chevrolet following suite in 1957. By the end of 1957 both GMC and Chevrolet trucks could be ordered from the factory with the NAPCO Powr-Pak conversion. The two offered identical systems other than the availability of a V-8 and an automatic transmission on the GMC trucks. The Chevy could only be ordered with the 235ci six cylinder and a four speed manual (although there was nothing stopping an owner from ordering whatever he or she wanted in a 2 wheel drive truck and then having a NAPCO Powr-Pak "upfitted" by the dealer)."

[G&R's57GMC]

The NAPCO conversion could be installed on any truck with whatever was on the truck.

So yes you could have a NAPCO with 3 on the tree, with or without O.D. , 4 on the floor or with a Hydramatic .

BTW the Hydramatic does have Park, to engage it you would put it in Reverse and when you turned the key off the PARK plunger would engage .

Does this seem odd to you today ?

Well back in the day it was common practice to put a MANUAL trans in Reverse when you parked.
So it wasn't a far stretch for GM to have the driver put the Hydamatic in Reverse.

Generally Reverse was the lowest gear in a manual trans and it would have a harder time turning the engine against compression.

More then a few vehicles ran away on hills when the driver didn't also set the parking (emergency) brake.