Reply
 
Thread Tools Display Modes
  #1  
Old 10-14-2025, 02:38 PM
78w72 78w72 is offline
Suspended
 
Join Date: Nov 2007
Location: iowa
Posts: 5,598
Default 301T engine mount brackets vs 350/400/455

Trying to figure out a weird part# issue on some engine side mount brackets, any of the part# gurus here able to make sense of this?

I have 2 sets of brackets, 1 from a 1981 turbo 301 TA and 1 set from a mid 70's small car with a 350 like a firebird or GTO, which are the same engine side brackets as 2nd gen firebird & TA with 400/455 engine, #496892 496893.
On the set from the 301T, one side is 496893 but the other side has a different part# or its a mis-stamp or hard to read... it looks like 496858 or maybe the last digit is a 3 or maybe 6?. Could the 5 be an upside down 9 and the last digit "8" really be an ugly 3 or 2?? Cant find much searching with the 496858, 3, or 6 as last digit. But it definitely came from the turbo TA, was still bolted to the engine when I removed it. It looks to be the same dimensions but has a slightly different contour on the top edge... maybe to clear a turbo part but still same bracket?? Anyone ever seen this part#?
Attached Thumbnails
Click image for larger version

Name:	bracket.jpg
Views:	25
Size:	13.0 KB
ID:	658668  


Last edited by 78w72; 10-14-2025 at 02:44 PM.
  #2  
Old 10-14-2025, 02:42 PM
78w72 78w72 is offline
Suspended
 
Join Date: Nov 2007
Location: iowa
Posts: 5,598
Default

This shows the different shape of the weird bracket... 1st pic is the 301 brkts, 2nd pic is the correct part#'s that have a slight indent or dip in the top edge of one.
Attached Thumbnails
Click image for larger version

Name:	bracket2.jpg
Views:	23
Size:	82.7 KB
ID:	658669   Click image for larger version

Name:	bracket3.jpg
Views:	19
Size:	79.5 KB
ID:	658670  

  #3  
Old 10-17-2025, 02:51 AM
Dens71TA's Avatar
Dens71TA Dens71TA is offline
Ultimate Warrior
 
Join Date: Jul 2002
Location: Midwest
Posts: 2,318
Default

496858 is RH bracket for '75-'81 A-body, '78-'81 G-body, and '77-'81 B-body. It's the lowest height of the clam shell motor mount brackets for Pontiac engines.

Seems unlikely the factory would have built it that way as it would cause the engine to be tilted. Parts book lists 496892/496893 for '75-'81 F-body.

The Following User Says Thank You to Dens71TA For This Useful Post:
  #4  
Old 10-17-2025, 05:31 AM
johnta1's Avatar
johnta1 johnta1 is online now
Ultimate Warrior
 
Join Date: Feb 2001
Location: now sunny Florida!
Posts: 22,515
Default

It seems like somewhere in the far reaches of my mind (probably cobwebs though) that the T301 was tilted to give more clearance to Turbo or something?

Been a long, long time ago when I read it.

Just food for thought maybe?


__________________
John Wallace - johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

Winner of Top Class at Pontiac Nationals, 2004 Cordova
Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats

KRE's MR-1 - 1st 5 second Pontiac block ever!

W.E.C moment


"Every man has a right to his own opinion, but no man has a right to be wrong in his facts."

"People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates
The Following User Says Thank You to johnta1 For This Useful Post:
  #5  
Old 10-17-2025, 09:34 AM
78w72 78w72 is offline
Suspended
 
Join Date: Nov 2007
Location: iowa
Posts: 5,598
Default

Thanks for the replies, and for confirming what years/cars the 496858 brkt is originally for. This 301t engine was bought as a parts engine and was already pulled from the car when I got it, so no clue if it was factory or put on after the fact for some reason? But they both look the same condition/age so whatever the reason, its been on there quite awhile.

Ive owned 4 or 5 of these turbo cars and about the same number of 301T engines and did a full subframe off resto of my 81 pacecar, but never paid much attention to the mount brackets or their part #'s. Cant say Ive noticed the 301t engines being tilted, they seem to sit square in the frame visually just like other 2nd gen Firebirds, what was changed was the turbo hood with the offset bulge to clear the offset carb on the turbo plenum.

Maybe this 301t was put in a later 70's-81 A, G or B body car?? Who knows, people did/do strange things with cars sometimes. But at least I know what the odd mount brkt is for so I can list it for sale. Thanks again!

Reply


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

Forum Jump


All times are GMT -4. The time now is 03:16 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017