6066 (1960-1966) GMC Truck Club Bitcoin now accepted here! 
Pay Dues
Pay Dues or become a Site Supporter
 



Go Back   6066 (1960-1966) GMC Truck Club > 6066 GMC Truck Club Forum > General Discussion


General Discussion Sit down and chat with fellow members! Any topics that don't fit other categories goes here.

Reply
 
Thread Tools
  #1  
Old May 11th, 2016, 04:22 AM
GMJakers13 GMJakers13 is offline
Junior Member
 
Join Date: Aug 2015
Location: Hanna, WY
Truck: 1962 K2500
Age: 28
Posts: 15
Rep Power: 57
GMJakers13 is on a distinguished road
Default 401 in a mid 70s crew cab

Hello everyone! As the title reads, going to try and stuff the 401im picking up next week into a mid 70s crew cab c30. And im wondering if anybody on here has done the swap into those year model trucks, and what tips or ideas you all might have. The transmission I may get at a later date is a 5spd OD. But the truck is setup for automatic and dont know if there is a flexplate for the 401, or where I might find one. but I do have an NV 4500 on hand.... anything and everything is appreciated!
Reply With Quote
  #2  
Old May 11th, 2016, 05:20 AM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: 401 in a mid 70s crew cab

If you're going to use an automatic then you will need the complete flywheel adapter housing flexplate from a Turbo 400 GMC pickup built from 66-69 provided you have the six bolt style flange crankshaft. Otherwise you can get a modern adapter setup from Bendtsens that just uses a flexplate and also requires a modern high speed reduction starter motor. Other things to consider are adapting earlier pickup V6 motor mount brackets to the frame and whether you are going to use an electric cooling fan or belt driven fan. If you use the belt driven fan then you will need the light duty pickup truck water pump housing which sits lower, that also requires using the 305,351 and 379 timing chain and sprockets which eliminates the 3 piece gear drive. I did a similar conversion on my 68 using the 478M but it was easier since the truck already was equipped with the 305E
Attached Images
File Type: jpg P1010009.JPG (429.6 KB, Multiple views, 16 clicks)
Reply With Quote
  #3  
Old May 11th, 2016, 05:46 PM
GMJakers13 GMJakers13 is offline
Junior Member
 
Join Date: Aug 2015
Location: Hanna, WY
Truck: 1962 K2500
Age: 28
Posts: 15
Rep Power: 57
GMJakers13 is on a distinguished road
Default Re: 401 in a mid 70s crew cab

Nice. And thank you. I will be seeing it next week but does the 401 have a 6 bolt crank flange, being that it shares the same stroke as the smaller 305and 351, or is it the 8 bolt? Ive been told this engine is externally balanced. If so, I could probably make a flexplate. Just need to know what material would need to be used.
Reply With Quote
  #4  
Old May 11th, 2016, 07:02 PM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: 401 in a mid 70s crew cab

Most are 6 bolt and later engines are 8 bolt, what year is the one you're getting?
Reply With Quote
  #5  
Old May 11th, 2016, 07:07 PM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: 401 in a mid 70s crew cab

Quote:
Originally Posted by bigblockv6 View Post
Most are 6 bolt and later engines are 8 bolt, what year is the one you're getting?
The 401 like the 305 and 351 are all internally balanced so there is no weight needed on the flywheel or flexplate
Reply With Quote
  #6  
Old May 11th, 2016, 07:21 PM
GMJakers13 GMJakers13 is offline
Junior Member
 
Join Date: Aug 2015
Location: Hanna, WY
Truck: 1962 K2500
Age: 28
Posts: 15
Rep Power: 57
GMJakers13 is on a distinguished road
Default Re: 401 in a mid 70s crew cab

Hallelujah! That makes things easier. Im not sure as to the year. Is there a reason they went from 6 to 8? Did things start coming apart? Again thanks. If its not external that means I can make am adapter kit no problem. The setup from Bendtsens is nice but a little pricey.
Reply With Quote
  #7  
Old May 11th, 2016, 07:33 PM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: 401 in a mid 70s crew cab

The 478 always had the 8 bolt flywheel, it's possible things may have not been holding up with a 6 bolt in later years because 401's were in larger 7500-8500 series trucks. In your case a 1 ton Crew Cab will be fine with the 6 bolt setup. If you can make your own adapter that will be cost saving.
Reply With Quote
  #8  
Old May 11th, 2016, 10:33 PM
Ed Snyder's Avatar
Ed Snyder Ed Snyder is offline
-= Dues Paid =-
 
Join Date: Jan 2013
Location: Medford, Oregon
Truck: 1962, 1965, 1967
Posts: 868
Rep Power: 343
Ed Snyder has a spectacular aura aboutEd Snyder has a spectacular aura aboutEd Snyder has a spectacular aura aboutEd Snyder has a spectacular aura aboutEd Snyder has a spectacular aura aboutEd Snyder has a spectacular aura about
Default Re: 401 in a mid 70s crew cab

Quote:
Originally Posted by GMJakers13 View Post
Hello everyone! As the title reads, going to try and stuff the 401im picking up next week into a mid 70s crew cab c30. And im wondering if anybody on here has done the swap into those year model trucks, and what tips or ideas you all might have. The transmission I may get at a later date is a 5spd OD. But the truck is setup for automatic and dont know if there is a flexplate for the 401, or where I might find one. but I do have an NV 4500 on hand.... anything and everything is appreciated!
Here are photos if the parts you'll need if you want to keep it stock, and not pay the big bucks for the Bendtsen parts. Note that the auto trans flywheel is different from the manual trans one. Send me a PM if you're interested in buying these parts.
Attached Images
File Type: jpg 66 #1.JPG (139.6 KB, Multiple views, 5 clicks)
File Type: jpg 66 #2.jpg (111.0 KB, Multiple views, 1 clicks)
File Type: jpg 66 #3.jpg (134.4 KB, Multiple views, 2 clicks)
File Type: jpg 66 #4.jpg (130.5 KB, Multiple views, 1 clicks)
File Type: jpg 66 #5.jpg (139.2 KB, Multiple views, 2 clicks)
File Type: jpg 66 #6.jpg (218.2 KB, Multiple views, 2 clicks)
__________________
Ed Snyder
Medford, Oregon
1962 1000 Pickup 401M & Muncie 318 with overdrive
1962 K1000 Suburban 401M & SM420
1965 2500 Suburban 351C & SM420 with Watson overdrive
1967 CM1500 pickup 351E & NP435
Reply With Quote
Reply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
crew cab Archiver Previous Forum Posts 0 February 23rd, 2005 12:53 AM
Crew Cab Archiver Previous Forum Posts 0 May 25th, 2004 01:53 AM
Re: [6066 GMC Truck] The Crew-Cab to end all Crew-Cabs Archiver Previous Forum Posts 0 February 1st, 2001 06:14 AM
Re: [6066 GMC Truck] The Crew-Cab to end all Crew-Cabs Archiver Previous Forum Posts 0 February 1st, 2001 02:25 AM
Crew cab Archiver Previous Forum Posts 0 November 29th, 2000 12:07 AM


All times are GMT +1. The time now is 09:04 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710489870|0