putting a 1971 pontiac 350 engine in the 68 bird and need some help finding out what motor mounts and brackets to use

1968 V-8 motor mounts is what you will need. (1968 V-8 frame mounts as well if you are converting from an OHC-6 If the car was a V-8, then you need only find the motor mounts.)

Any other "brackets" that are you referring to? Such as accessory brackets?

thank you for quick responce did not know if the engine would sit in the proper position with the 68 engine brackets

It's all about the blocks and their mounting holes. Pontiac used the same mounting locations and added extra holes in the later blocks to accommodate the different body styles that the motor might drop in to. The '71 block should have 5 drilled and tapped motor mount holes on each side. You'll only need to use 2.

Prior to 1970, the Firebird (F-body) and Tempest (A-body) body styles used the same motor mount holes. The Firebird was changed in '70, but the Tempest stayed the same, hence the multi-use requirements. Some later blocks - 1977, for example - don't always drop in to the Firebird without the proper adapters.

Never mind (Quenton beat me to it and provided more detail anyway)

Welcome to the site just the same.

thank you for info sorry so late in geting back but got busy at work.GREAT INFO THANKS AGAIN

I own a 1967 Firebird Convertible with a 1971/72 Pontiac 400. Original engine was a 326.
Problem: My harmonic balancer is about an 1/16" to 1/8" from the K frame.
Could this be because of incorrect motor mounts being used?

Hey now, no Mopar references

It could also be the late model harmonic balancer being larger or the crank pulley (on mine the pulley is larger than the balancer). I know the subframe crossmember has a niche in it to help clear both.

Sorry about that. Won't happen again.
Slip of the tongue and that I was also discusing it with a mopar guy here at work.

No notch in my subframe and motor mounts look to be correct.
Are the sub frames different from first gen to second gen firebirds?

Yes, they are very different and use completely different motor mounts. But the blocks are the same.

I believe that the early 326 used a different balancer design than the 400 and the all later (68 and up) motors. That may be why there's less clearance and no notch. I have a 67 and 69 subframe I can check out later to compare the two, but I don't have a 326 balancer to look at to see if I am correct. Perhaps one of the other guys here with more than one car can compare for you.

I am guessing that they just dropped in a 72 400 without using the 326 pulleys and what not.

What are you thought of cutting in a notch into the cross memeber? Just enough so that I could change a belt without lifting the engine...

I would have to look at the design of the subframe just to be sure that the notch isn't welded shut. Unless you can cut it and then weld it ... all speculation on my part.

Does not look like the notch was welded shut. Just no visible notch.
Thought about looking into the harmionic balancer.
I think I am going to have to resort to shimming the motor mounts.
Anyone have any experience with shimming motor mounts?

67-69 F, 65-70 B, 72-74 X bodies used the same mounts.
Everything else is diff.
67 and earlier engines have a shorter crank with smaller dia balancers, but later models fit no problem.
I've had 62 thru 78 combos in mine over the years.

Looks like the back side of the cross member does angle down to form a low spot (notch). However, the first belt groove of the pulley/balancer still sits over the cross member leaving me no room. Will have to do some additional detective work.

Numbers on the motor tell me its a 72 Pontiac.

Engine Code YX/CO36223
Date Code: H251
Engine Casting#: 481988
Engine VIN#: 22P305020

Realized i didnt give all the info.
Thats mounts only, not brackets.
The 72 should be a direct bolt in IF your car has the 4 correct mount "brackets".
If all 3 mounting points are correct, the balancer will clear the x-member.

I wonder if the trans mount might be too tall, tilting the front of the engine too far down? I looked at three subframes last night. Each has a top-hat section in the lateral cross-member joined with a flat (what looks like) rectangular tie-in. I wouldn't want to cut anything in this area without being able to reinforce the cut-out section. The forward lateral carries little load, but the rear one carries a lot of the cornering loads.

OK. Still trying to figure out why the crank pulley is sitting so close to the cross member. After looking at one at a car cruise I believe that the engine is mounted to far forward. I was unable to view the engine compartment to look at the motor mount locations but went back and looked at mine.
If the front of the car(driver side)is to your left I have one mount hole open then the motor mount is bolted to the next one in line.

1)Does anyone know which mounting holes are suppose to be used on a 1972 400 block for mounting in a 67 bird?
2) Are there additional holes for mounting the tranny cross memeber further back?

From memory, the forward ones.
Should have about an 1" between block and firewall(hate that term).

That's what I thought.
I think by using the second mounting hole the engine is to far forward. Leaving about 3 inches from the distributor and the FW and placing the crank pulley directly over the cross member.
Maybe the first hole was not tapped. I read that not all mounting holes were always tapped.
Now I have to see if I can move the transmission support back or see if the tranny has other mounting holes as well.
Thanks