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Motor mount material

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Old Jul 9, 2023 | 12:29 PM
  #1  
//<86TA>\\'s Avatar
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From: Central NJ
Car: 86 Trans Am
Engine: 408 stroker sbc
Transmission: TKO600
Axle/Gears: Moser full floater m9, 3:70 trutrac
Motor mount material

It's been a while since I was active, not sure where everyone here is on their opinions and experiences with different motor mounts.
What's the better material these days? What's the best go-to for a hot street car with a pro-touring vibe?
stock rubber?
Poly (tends to raise engine)
Solid (harsh)
something else???
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Old Jul 9, 2023 | 12:36 PM
  #2  
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From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Motor mount material

Stock rubber...
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Old Aug 28, 2023 | 02:02 AM
  #3  
Zach/90\irocZ's Avatar
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From: San Diego, California For Now
Car: 88 Formula, 90 Iroc RIP, 92 RS Sold
Engine: 305 to 350
Transmission: 700r4
Axle/Gears: 10 Bolt
Re: Motor mount material

just don't go solid.
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Old Aug 28, 2023 | 08:19 AM
  #4  
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From: Cincinnati, OH
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Re: Motor mount material

I am running solid mounts and it is nowhere near as brutal as I thought it would be. Can't really tell the difference to be honest with you.
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Old Aug 28, 2023 | 02:46 PM
  #5  
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From: Grand Rapids, MI
Car: '87 TA
Engine: 6.0LS
Transmission: 4L80e, 3000 stall
Axle/Gears: DIY 9 inch, 3.00 gear
Re: Motor mount material

I run factory rubber mounts and a poly trans mount. Cant tell the difference. Im sure if you had a stock engine it would be noticeable but for those us us with cammed engines with lumpy idles it will have vibrations regardless.
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Old Aug 28, 2023 | 02:59 PM
  #6  
midias's Avatar
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From: Henrietta NY
Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: Motor mount material

Running poly with a XE274 cam and a 350. There is some vibration but it is not bad. If you have a very low idle for that lumpy sound it may be worse.
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Old Aug 29, 2023 | 08:40 AM
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From: Louisville, KY
Car: 1983 Z28
Engine: 385 Fastburn
Transmission: T-5
Axle/Gears: BorgWarner 9-bolt posi, 3.27 gears
Re: Motor mount material

I'm running poly all around, no weird vibrations, does the job well.

What i've read (for what that's worth) is that you just want to make sure whatever you use in the motor mounts you also use on the trans mount and torque arm mount.
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Old Sep 3, 2023 | 01:51 PM
  #8  
//<86TA>\\'s Avatar
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From: Central NJ
Car: 86 Trans Am
Engine: 408 stroker sbc
Transmission: TKO600
Axle/Gears: Moser full floater m9, 3:70 trutrac
Re: Motor mount material

I had poly on the car since 07 or so, only complaint was that it raised the engine which, for me, caused a couple small problems.

I appreciate the feedback, I'm probably going to just use rubber and see how it holds up.
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Old Sep 3, 2023 | 07:55 PM
  #9  
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From: NJ
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: Motor mount material

I run the polyurethane ones from energy suspension on the engine mounts
on the transmission, I have a rubber one.
this has worked well for 4 years of hard use
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Old Sep 3, 2023 | 08:23 PM
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From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Motor mount material

I have had Poly on my G20 and my Express van for more than 10 years. Holding up well. The poly mounts put the engine where it was designed to be and keep it there, had to install them on the Express van to get the Doug Thorley headers to fit as the old ones had sagged. When you replace the worn, sloppy, loose rubber mounts with poly, your throttle response will feel a lot better. The motor no longer moves around under the hood when you step on the throttle. I will never put rubber anywhere in the engine/trans mounting or suspension again.


Last edited by Fast355; Sep 3, 2023 at 08:26 PM.
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