C-3 motor mount fit

[Owen L.]

I'm having some difficulty obtaining motor mounts for my '72. I believe the common part interchange # is 2285. The first pair (Westar) from Rock Auto were too narrow to fit over the frame horns. The second set (Anchor brand) from a local Car Quest Auto Parts store are a bit sloppy with 3/16-1/4" gap to fill. My originals (I believe) seem to be a nice slip-fit but both have a big crack in the rubber circumference where it meets the larger plate so I don't want to reuse them.

Are the larger-gap-than-necessary fine to use as is? Should I use flat washers to fill the gap? Should I continue looking for a better fitting pair?

[Richard G.]

Re: C-3 motor mount fit

I would try another style.
You have your choice, Korea or China.
I would try my local Napa store.
Bring the originals and ones that didn't fit with you to the store, if you can, for a match up.
Just to reduce the likelihood you are not looking the same manufacture's part just in a different package.
Once in a while I get lucky and find a NOS part on Ebay. Or even just and older aftermarket part.
Sometimes even old enough to be made in the USA!
Best of Luck.
Rick

[Patrick H.]

Re: C-3 motor mount fit

Don’t waste your time at parts stores. As you see, they don’t fit.

Corvette Central came out with a reproduction a few years ago, and they FIT!
Order a set and be happy.

[Owen L.]

Re: C-3 motor mount fit

Don’t waste your time at parts stores. As you see, they don’t fit.

Corvette Central came out with a reproduction a few years ago, and they FIT!
Order a set and be happy.

My excitement balloon is totally deflated; they won't be available until September.

[Bob W.]

Re: C-3 motor mount fit

Owen, Call Paragon and ask who makes their motor mounts. I have bought parts from them that came from CC Li with a Paragon label.

[David L.]

Re: C-3 motor mount fit

Owen,
I have a pair of Napa Balkamp motor mounts, # 602-1106, ("Engine Mounting Replacement Unit No. 3990914 - Right Hand or Left Hand" as stated on the instruction sheet) listed for 58-69 Chevrolet, 67-69 Camaro 68-69 Chevelle and 64-69 Chevy II models (283,307,and 327 engines). The metal part is stamped "MADE IN USA" and the box was "MADE AND PRINTED IN THE U.S.A." I also have a pair of similar motor mounts in boxes labeled "Rockhill Motor Mounts 2285". Each mount comes with a bolt, 2 washers, and a nut. I bought them years ago at swap meets and have no use for them.
Dave

[Joe L.]

Re: C-3 motor mount fit

Owen,
I have a pair of Napa Balkamp motor mounts, # 602-1106, ("Engine Mounting Replacement Unit No. 3990914 - Right Hand or Left Hand" as stated on the instruction sheet) listed for 58-69 Chevrolet, 67-69 Camaro 68-69 Chevelle and 64-69 Chevy II models (283,307,and 327 engines). The metal part is stamped "MADE IN USA" and the box was "MADE AND PRINTED IN THE U.S.A." I also have a pair of similar motor mounts in boxes labeled "Rockhill Motor Mounts 2285". Each mount comes with a bolt, 2 washers, and a nut. I bought them years ago at swap meets and have no use for them.
Dave

Dave------


While it has many GM applications, the 3990914 is not applicable to Corvettes.

[David L.]

Re: C-3 motor mount fit

Dave------
While it has many GM applications, the 3990914 is not applicable to Corvettes.

Joe,
I assume that Owen is looking for 2285 motor mounts that will actually fit properly on his 72 Corvette. The Anchor company lists the 2285 motor mount as a replacement for the 72 Corvette on their web site. My Napa 602-1106 motor mounts have "2285" molded into the rubber and came with a 3990914 instruction sheet that is almost identical to the instruction sheet inside a GM 3990914 box. Apparently the 2285 mounts will fit on a Corvette even though they are not applicable.
Dave

[Joe L.]

Re: C-3 motor mount fit

Joe,
I assume that Owen is looking for 2285 motor mounts that will actually fit properly on his 72 Corvette. The Anchor company lists the 2285 motor mount as a replacement for the 72 Corvette on their web site. My Napa 602-1106 motor mounts have "2285" molded into the rubber and came with a 3990914 instruction sheet that is almost identical to the instruction sheet inside a GM 3990914 box. Apparently the 2285 mounts will fit on a Corvette even though they are not applicable.
Dave

Dave------


The motor mount used for 1970-72 Corvettes was GM #3980701. In SERVICE it was known as GM #3990916 since this part number included bolt, nut and washers. Part number 3980701 was embossed on the mount included with the 3990916, though. I am certain of this since I have many 3990916 [none for sale]. The 3990916 was also SERVICE for all 1963-72 Corvettes until it was replaced by the GM #6258154 in February, 1977. The latter part number included mount GM #330973 which is the mount used in PRODUCTION for 1973-82 Corvettes.

I do not know how the mount included with the GM #3990914 differed from the 3990916. However, there had to have been some difference whether or not it affects cross usability.

[Owen L.]

Re: C-3 motor mount fit

Owen, Call Paragon and ask who makes their motor mounts. I have bought parts from them that came from CC Li with a Paragon label.

I asked Paragon, Zip, and Ecklers for info on their mounts.

Paragon stated that they're Anchor 2267s which doesn't really make sense as direct replacements because the 2267's on Amazon, Rock Auto, AdvanceAuto, and Summit don't appear to match my old ones because the ears don't have the extra washers welded on. (Difficult to see this detail on the Paragon site.)

Will update as I hear from the other two.

[Owen L.]

Re: C-3 motor mount fit

Joe,
I assume that Owen is looking for 2285 motor mounts that will actually fit properly on his 72 Corvette. The Anchor company lists the 2285 motor mount as a replacement for the 72 Corvette on their web site. My Napa 602-1106 motor mounts have "2285" molded into the rubber and came with a 3990914 instruction sheet that is almost identical to the instruction sheet inside a GM 3990914 box. Apparently the 2285 mounts will fit on a Corvette even though they are not applicable.
Dave

More engine mount oddities in this odyssey!

The Napa website for 602-1106 says it's a Pioneer 602267 in the . (https://www.napaonline.com/en/p/BK_6021106)
They're also the same 2267s that Paragon sells as replacements but Summit and Napa both say it won't fit.

I believe the 2285 is the proper replacement but the problem has been that there seems to be inconsistencies of manufacturing that results in either too much slop or too tight. Maybe the solution is to check multiple boxes from local parts dealers to assemble a pair that fits the way they should.

[Joe L.]

Re: C-3 motor mount fit

Joe,
I assume that Owen is looking for 2285 motor mounts that will actually fit properly on his 72 Corvette. The Anchor company lists the 2285 motor mount as a replacement for the 72 Corvette on their web site. My Napa 602-1106 motor mounts have "2285" molded into the rubber and came with a 3990914 instruction sheet that is almost identical to the instruction sheet inside a GM 3990914 box. Apparently the 2285 mounts will fit on a Corvette even though they are not applicable.
Dave

Dave------


The 2285 is the aftermarket replacement part number for the GM #3990916 and is the 1963-82 Corvette locking-style mount. (2249 is the aftermarket part number for the original non-locking mounts).

The 2267 is the aftermarket replacement part number for the GM #3990914 which is used for many other Chevrolet models.

I have compared examples of the 3990916 (includes mount GM #3980701) and 3990914 (includes mount GM #3989488 or 3991271). These mounts are substantially different. I highly doubt they could be used interchangeably.

[John S.]

Re: C-3 motor mount fit

You might try Bairs, I ordered a set for my 73 about 5 years ago and they fit great. Washers welded to the ears of the mount as you describe. One was a little snug so I filed it a bit.

[Owen L.]

Re: C-3 motor mount fit

You might try Bairs, I ordered a set for my 73 about 5 years ago and they fit great. Washers welded to the ears of the mount as you describe. One was a little snug so I filed it a bit.

Huh. I never considered filing the too tight pair. I'll have to check them again to see how much would be required.

I'll look up Bairs - not familiar with them. Thanks.

[John S.]

Re: C-3 motor mount fit

Owen, if you have the latest Driveline (the COVID front cover), Bairs is on page 23. I hope they can help you out.