[Rob79]

Yanked the 301 rebuilt the 400 (1975 Block). New motor mounts. had one mount bracket from the 400 (driver side) had to steal passenger side bracket from the 301. In the catalouges I have they list as the same part. right? Well I fought the 400 into the engine compartment with the headers on because I counldnt get them on with the engine in. (real fun time) Know I can only get one bracket to fall into place. One side or the other but not both. I noticed that the T/A has another set of motor mount holes in the cross member.so I picked the engine a little bit and pulled the passenger side mount (almost as much fun as setting the engine) but the bolt spacing on the upper set of holes is spaced just a touch further apart than the lower ones. I can get the bolts in but they are at a pretty nasty angle (bolt heads pointing towards each other. What I need to know is should I be bolting the mounts in these holes or do they bolt in the same location that the 301 setup does? or do I need different brackets or mounts? My info tells me that the mounts and brackets are the same but this baby just doest want to fall into place. Like I said I can land one side or the other but not both. Pulling the motor back out of the engine compartment will be nearly if not totally impossible shy of tourching the headers in half. (flowtech's by the way)
Thanks
Rob

[Rob79]

Yanked the 301 rebuilt the 400 (1975 Block). New motor mounts. had one mount bracket from the 400 (driver side) had to steal passenger side bracket from the 301. In the catalouges I have they list as the same part. right? Well I fought the 400 into the engine compartment with the headers on because I counldnt get them on with the engine in. (real fun time) Know I can only get one bracket to fall into place. One side or the other but not both. I noticed that the T/A has another set of motor mount holes in the cross member.so I picked the engine a little bit and pulled the passenger side mount (almost as much fun as setting the engine) but the bolt spacing on the upper set of holes is spaced just a touch further apart than the lower ones. I can get the bolts in but they are at a pretty nasty angle (bolt heads pointing towards each other. What I need to know is should I be bolting the mounts in these holes or do they bolt in the same location that the 301 setup does? or do I need different brackets or mounts? My info tells me that the mounts and brackets are the same but this baby just doest want to fall into place. Like I said I can land one side or the other but not both. Pulling the motor back out of the engine compartment will be nearly if not totally impossible shy of tourching the headers in half. (flowtech's by the way)
Thanks
Rob

[Maurice Hood]

I installed a 1974 455 in a 1980 Firebird. I used all the frame and motor mounts for a 1979 Firebird and the engine fits in perfectly by just bolting everything back in the same spot that it came out of. Those mounts and brackets do have a left and right side to them.The best way to install the engine is to set the engine in and when the mounts are about 3 to 4 inches from coming together set the headers in and loosely start the bolts ( this is a lot easier with "2" people ). Then finish setting the engine down and install the long bolts into the mounts. Hope this helps... Maurice

[Brian Baker]

The 301 mounts are the same as the 400, don't move them. Get some help and muscle the engine around while it's lifted. Try different settings between the chain and the hoist, or different mounting locations of the chain to the engine to get a better angle at dropping it over both chassis mounts simultaneously. I replaced the 403/th350 in my 79 with a 455/th400, and although it wasn't too much hassle, it wasn't a stroll in the park either. Had to fully install the headers (snugged down) while engine was still lifted with hoist about 4-6" above the chassis mounts. Don't know about the quality of fit with your headers (I used Hooker S/C's), but it is possible they may be what is holding you up. There's a support brace on the subframe that runs from the frame to the rearmost bolt housing for the lower control arm on each side. The one on the passenger side may be in contact with your headers (mine were close). Keep at it and be patient, it'll fit.

[JC455]

Rob,
I used Flowtechs on my 68 LeMans- they were installed afterwards.
What I did was get the engine in place, then disconnect the motor mount through bolt, use the cherry picker to lift that side up enough and install the header. I then lowered the engine back down and reinstalled the bolt. Do the same to the other side and you should be in business.
FYI- you need to remove the oil filter adapter/filter before putting the pass side on.
It also helped me to file the second bolt hole on each side so the bolt could slip in easier, dimple the tube next to the solenoid for clearance, and file the dipstick tube flange area for a little addtional clearance.
These last comments were strickly for ease of install on MY car, yours may not require anything.
Good luck,


------------------
John

PS- I went to Harbour Freight Tools and purchased their angled head wrench kit- $20.00 w/ lifetinme warranty- for the 7/16" angle head wrench required to tighten the bolt on the firewall side of the center tubes (passenger side). I couldn't see paying the MAC/Snap On guy $25.00 for one stinkin' wrench.

[This message has been edited by JC455 (edited 07-16-2000).]

[STripleduce]

I found that useing solid block mounts & chevy pad mounts worked best for me.The solid mounts (if I remember correctly) were on 72 Fire bird formula w/ac.This also increased header clearence.

[STripleduce]

Also make sure holes on pad mounts are 16.5 inches apart.

[STripleduce]

I found that useing solid block mounts & chevy pad mounts worked best for me.The solid mounts (if I remember correctly) were on 72 Fire bird formula w/ac.This also increased header clearence.This will makit alot easier installing headers from underneath.