Hey there guys,

Im going to be installing a set of Kooks LT headers with a catted y-pipe in 2 months along with a MWC Fab 9" with their adjustable LCAs.
(likely will go with Heim/Poly, opinions welcome on other options, but please state why/pros/cons as im trying to learn).

Wondering what motor mounts and trans mounts I should put in to replace the 28 yr. old stock ones. It sounds like you should replace both motor and trans mounts at the same time not just one or the other.

I've seen that there are motor mounts and motor mount inserts available, what is the difference!? (or do you need both, yes im that much of a rook & still learning from y'all )

There were a few of old posts that said the prothane mounts are great HOWEVER many members had vibration issues, some worse than others as it seems to bring out other vibration issues present. Truly just want to prevent a headache after install and don't want to take everything apart again due to violent vibrations.

Will also be changing spark plugs (TR55), Wires (MSD Superconductors), and Ignition Coil (MSD Blaster) since it will be easier to access with the stock headers off.

Car is a 93 Formula with 40k miles that is a street daily driver, current mods are GMMG catback, Koni shocks, and Strano springs.

 

LS1 trans mount is a popular option. They are supposedly more sturdy than the LT1 mount. I have prothane motor mounts. Never had any problem with vibration that I'm aware of. It's either that or stock ones. If you go stock I believe you'll save yourself a bunch of money if you buy the mounts only without the clamshells. Clamshells are easily manageable with drilling out the rivets and putting bolts in their place.

 

I originally put in solid motor mounts and drove that way for a few years. Definitely regretted it because of how intense the vibration was. Would have been fine for a drag car, but not a daily! Ended up replacing with some poly mounts that you put inside your stock clamshell. (so just the inserts) As the previous post mentioned, pretty easy project just drilling out and bolting back together. With the exhaust manifold off, will be easy to access. Here is a pretty good write up.

https://ls1tech.com/forums/generatio...r-written.html

 

I used Energy Suspension poly for both the motor and trans mount. There's a slight vibration at times but it's not bothersome. Good option for the cost.

My engine is pretty mild, so the vibration might an more noticeable on engine with a big cam and rough idle.

 

I'm running energy suspension both motor and trans. Not a big deal on a M6 car. Slight vibration on take off.

 

ES "black" mounts (inserts) in stock clam shells and rubber (stock) trans mount. IMHO you don't want poly all the way around on a street car..

 

Agreed
This is my favorite combo too.

 

I could be wrong, but I think my SS with Level II suspension has poly bushings all the way around.

 

The black ES mounts have graphite impregnated in them which helps against the "polly squeak" often associated with poly (red) mounts

If the car is primarily a auto X track car than solid mounts or red polly all around....but it will have considerably more driveline harmonics transmitted throughout the car

I find, for me the ES black motor and stock rubber trans (T56) work great and no noise or driveline vibes transmitted to the car body

 

Went ahead and took your guys advice, got the black energy suspension for the motor and stock rubber mount for the transmission at advanced auto parts for around $16.
I would have gone with the LS1 mount if I had more certainty of fitment and benefit but couldn't find enough information. Will be doing the install right after the new year.
Thank you for the help guys!