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 > GMC V6 and V12 Engines


GMC V6 and V12 Engines Engine repair and rebuilding

Reply
 
Thread Tools
  #1  
Old April 22nd, 2018, 02:49 PM
vanhow10 vanhow10 is offline
Junior Member
 
Join Date: Nov 2013
Location: Moore, OK
Truck: 1965 K1000
Age: 65
Posts: 5
Rep Power: 0
vanhow10 is on a distinguished road
Default I Beam Exhaust on 305C

Bought a 305C with the I-beam exhausts and automatic transmission set-up. It came out of a long-bed stepside that the owner thought was a 3/4 ton truck. Is there any difference in the heads or anything else I should figure out considering it has the I-Beam exhausts? Thanks for any input.
Reply With Quote
  #2  
Old April 23rd, 2018, 05:02 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: I Beam Exhaust on 305C

Just because your 305C has I beam manifolds doesn't mean there are differences in the head, these are still the same small port heads and exhaust manifolds. Lately I've noticed a lot of people thinking just because their V6 has I beam manifolds that they are Magnums. The fact is when GMC first introduced the V6 for 1960 there were no big port Magnum engines yet there were I beam shaped exhaust manifolds. Just a few minutes ago I got a message on youtube from someone saying I'm using 305 exhaust manifolds on my 478M, well just because they're not I beam shaped and are a smooth casting. I'm using 351E Magnum exhaust manifolds retain the proper look for a pickup truck. There were actually 5 different types of Magnum Exhaust manifolds.
Reply With Quote
  #3  
Old April 23rd, 2018, 05:15 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: I Beam Exhaust on 305C

Quote:
Originally Posted by bigblockv6 View Post
Just because your 305C has I beam manifolds doesn't mean there are differences in the head, these are still the same small port heads and exhaust manifolds. Lately I've noticed a lot of people thinking just because their V6 has I beam manifolds that they are Magnums. The fact is when GMC first introduced the V6 for 1960 there were no big port Magnum engines yet there were I beam shaped exhaust manifolds. Just a few minutes ago I got a message on youtube from someone saying I'm using 305 exhaust manifolds on my 478M, well just because they're not I beam shaped and are a smooth casting. I'm using 351E Magnum exhaust manifolds retain the proper look for a pickup truck. There were actually 5 different types of Magnum Exhaust manifolds.
What I would like to add is the fact that your 305C has I beam manifolds also means they do have bigger and smoother passages over the round type commonly used on light duty trucks and most 305C engines.
Reply With Quote
  #4  
Old April 25th, 2018, 12:04 AM
vanhow10 vanhow10 is offline
Junior Member
 
Join Date: Nov 2013
Location: Moore, OK
Truck: 1965 K1000
Age: 65
Posts: 5
Rep Power: 0
vanhow10 is on a distinguished road
Default Re: I Beam Exhaust on 305C

Thanks for the input, I thought that might be the case, but wanted to get a second opinion. I plan on keeping a 305 in the truck whether it be a C or E. It will just depend on which one seems to be in the best shape. I also got an original transmission adapter plate with the 305C so I'm hoping to change to an automatic transmission as I put things back together.
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
Re: anyone have an extra I-beam exhaust manifold Archiver Previous Forum Posts 0 January 9th, 2010 01:21 AM
anyone have an extra I-beam exhaust manifold Archiver Previous Forum Posts 0 January 8th, 2010 12:32 AM
Re: 6066gmc I beam Exhaust manifolds Archiver Previous Forum Posts 0 July 13th, 2008 05:30 AM
6066gmc I beam Exhaust manifolds Archiver Previous Forum Posts 0 July 13th, 2008 01:42 AM
I-Beam Exhaust Manifolds Archiver Previous Forum Posts 0 June 30th, 2006 01:42 AM


All times are GMT +1. The time now is 04:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710429451|0