Any one have experience with big block poly motor mounts?

Do they come in two sizes also (short/fat, tall/skinny)? Which one do I need?

Looking at the Energy Suspension kind...

thanks guys

Tall & Narrow Type, available in 2 finishes:
#3.1117 has a zinc finish
#3.1118 has a chrome finish
See diagram. Inside Width- 2 3/8"
Height Base to Bolt Center- 2 3/16"
Replaces O.E. part numbers: 3962740, 3990918, 3962748

what are the short/ fat ones for?

thanks

The lower hp motors!

I think David P. has pic's and dimensions and applications listed on his great site if you want to go over and look around there.

pdq67

69 mounts are thicker narrower, the 67 and 68 mounts are thinner and wider.

It really depends on what year frame brackets you have. The thicker 69 mounts require shorter height frame brackets.
The energy suspension mounts are interlocking so are all safer to use.

I have the original 67 subframe, so I guess i need the shorter fatter kind?

Does the energy suspension kind have a big block set (one a little taller for the motor offset?)

thanks guys

Big Blocks in 67/68 used GM part number 6258154 in 69 and later they used 3990918 GM part number. (all info from David Pozzi's great web site) These GM numbers sub to either mount !

Short & Wide Type Early General Motors Style MOTOR MOUNTS,
2 Types (short & wide and tall & narrow):

Short & Wide Type, available in 2 finishes:
#3.1114 has a zinc finish
#3.1115 has a chrome finish
See diagram. Inside Width- 2 5/8"
Height Base to Bolt Center- 1 3/4"
Replaces O.E. part numbers: 3990914, 3960768, 6258154
Replaces aftermarket numbers: 2267, 2285, 2142
This type/size chrome motor & transmission mount set is #3.1133.
This type/size zinc motor & transmission mount set is #3.1120.
NOTE: MUST USE SUPPLIED BASEPLATE.

Tall & Narrow Type Tall & Narrow Type, available in 2 finishes:
#3.1117 has a zinc finish
#3.1118 has a chrome finish
See diagram. Inside Width- 2 3/8"
Height Base to Bolt Center- 2 3/16"
Replaces O.E. part numbers: 3962740, 3990918, 3962748
Replaces aftermarket number- 2283
This type/size chrome motor & transmission mount set is #3.1134.
This type/size zinc motor & transmission mount set is #3.1122.
NOTE: MUST USE SUPPLIED BASEPLATE.

***Please Note***
The tall and narrow '69 mounts will not fit on the short and wide frame stands ! So contrary to my previous post, you should use the short and wide mounts !
I only have experience using these on small blocks !

To use the short and wide mounts in poly for a big block you are going to need the big block trans cross memeber and motor perches for them to work right, I just got a set of poly for a 69 Car converted to a big block and without the right cross memeber & perches your going to be fighting it all day. I found it much easier to mount the trans first then to swing the motor into the right place to get the motor mounts to fit right, it takes some time to get them in the right place. Also remember, at this point it is much easier to drop the motor in and then place the headers in place with the motor up off the motor perches then lower it in to place. take car with the steering box side because it is a little tight. I fought this conversion all nite last nite on a friends Camaro, and yes he is a good friend or I would have charged him a large bill to drop the motor.

Funny, but my BB install went about a smooth as any SB install I had ever done.

I did buy NOS BB frame mounts and the right poly mounts tho for better/easier header fitment.. As well as a BB Z-bar.. Still had to dimple onna my Heddman's pass. side tubes even with everything being about BB stock....

And I used my SB, M-20 crossmember by using a 3-hole poly mount and installing one bolt in the middle hole through the pass. side hole in the crossmember! I just kicked the tranny tailhousing over and bolted it up..

AND it was a bit of a hassle to hook up my Muncie shifter tho b/c it is darn tight up in there to put the stock torque rod on it!!

I even installed my motor with my M-20 on it over the drivers side fender by twisting it down in the hole as I dropped it BY MYSELF!! The Cherry-picker was too short by about 6" or so to go in from the front so I went in from the side! Plus I had about a 3/4" to an inch floor to driveway drop!! Woulda made moving the loaded picker in and out a real bi-ch!!

As Arnald woulda said, "No problemo!!"...

pdq67

Funny thing about them short and wide mounts, I just found out today they are the wrong ones for a 69. That might have been the reason I had such a pain, I guess you live and learn.