Motor Mount Perches? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jack15T · 05-01-2019, 08:01 PM

Hi Folks, I have been trying to replace the Motor Mount Perches in my 1971 Chevy K20 Pickup. The VIN number states the truck came with a V8. Some previous owner stuffed a 454 in it, using the what I think is the original Crossmember and Perches which should have been for a Chevy 350. The 454 is hitting the firewall in two places. I want to move it forward but I cant find replacement perches. Mine are badly worn. Does anybody recognize these? One picture is the crossmember and the other picture is the Perch that came out of the Truck and the other Perch is what LMC sent me for a Small Block V8. If anybody can ID my Crossmember and Engine Perches I would greatly appreciate it. Cheers, Jack

**Grumpy old man** · 05-01-2019, 08:07 PM

Lock Doc picture

Jack15T · 05-01-2019, 08:18 PM

Thanks for the picture. None of those look like mine. There are no other holes in my frame that would suggest a different crossmember and the ones in your picture won't even come close to bolting up.

Mike C · 05-01-2019, 09:12 PM

You have a four wheel drive truck and all of the other perches are from 2x4 trucks. Move the entire crossmember and mounts forward. Unlike a 2x4 truck, the suspension is not attached to the crossmember.

Jack15T · 05-01-2019, 09:23 PM

That's what I planned on doing but my Perches are pretty worn. I would like to replace them. Any idea of a source? I tried Brothers, LMC, Classic and a couple of others. No luck.

Jack15T · 05-01-2019, 09:35 PM

Well, I found the perches on page 149 of the 67-72 factory assembly manual. Still doesn't help me any as I don't have a part number or a source for them.

**71blksuper4x4** · 05-01-2019, 10:18 PM

To my knowledge, they aren’t reproduced. What is the worn area you speak of?

tj1970cst · 05-02-2019, 06:57 PM

The hole on your mount isn't that bad. The big block trucks had a larger hole than the small block trucks.

Jack15T · 05-03-2019, 12:10 AM

The 71 K20 didn't come with a big block. I believe it was an option on the C models. Supposedly my perches are for the small block 350. I'm thinking there should be a bushing or something to take up the space around the skinny ass bolt that goes through that hole. The other perch is much worse than the one in the photo. I held the new engine mount up to the old perch and it does seem to fit marginally okay, but it sure leaves a lot of room for slop. I would think the GM engineers would have come up with something a little better. That being said I just finished tearing down my NP205 transfer case and rebuilding it. I'm not sure what planet the guy was from who designed that case but clearly no thought was given to rebuilding it. Thanks, Jack

notsolo · 05-04-2019, 10:35 AM

These were from a 72 K5 Blazer 350/350...NP205 transfer case.....can post in for sale section if your interested....LMK

**HO455** · 05-04-2019, 10:47 AM

It is possible that square body BBC perches were used as they may have junk yard items when your truck was converted.

Jack15T · 05-04-2019, 11:33 AM

Anything is possible with this truck.

Jack15T · 09-07-2019, 10:13 AM

NotSolo, Do you still have the perches? Jack

05-01-2019, 08:01 PM	#1
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Motor Mount Perches? Hi Folks, I have been trying to replace the Motor Mount Perches in my 1971 Chevy K20 Pickup. The VIN number states the truck came with a V8. Some previous owner stuffed a 454 in it, using the what I think is the original Crossmember and Perches which should have been for a Chevy 350. The 454 is hitting the firewall in two places. I want to move it forward but I cant find replacement perches. Mine are badly worn. Does anybody recognize these? One picture is the crossmember and the other picture is the Perch that came out of the Truck and the other Perch is what LMC sent me for a Small Block V8. If anybody can ID my Crossmember and Engine Perches I would greatly appreciate it. Cheers, Jack Attached Images

05-01-2019, 08:07 PM	#2
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Motor Mount Perches? Lock Doc picture Attached Images __________________ 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop

05-01-2019, 08:18 PM	#3
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? Thanks for the picture. None of those look like mine. There are no other holes in my frame that would suggest a different crossmember and the ones in your picture won't even come close to bolting up.

05-01-2019, 09:12 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,715	Re: Motor Mount Perches? You have a four wheel drive truck and all of the other perches are from 2x4 trucks. Move the entire crossmember and mounts forward. Unlike a 2x4 truck, the suspension is not attached to the crossmember. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

05-01-2019, 09:23 PM	#5
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? That's what I planned on doing but my Perches are pretty worn. I would like to replace them. Any idea of a source? I tried Brothers, LMC, Classic and a couple of others. No luck.

05-01-2019, 09:35 PM	#6
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? Well, I found the perches on page 149 of the 67-72 factory assembly manual. Still doesn't help me any as I don't have a part number or a source for them.

05-01-2019, 10:18 PM	#7
71blksuper4x4 SWB 4x4 Collector Join Date: Jun 2001 Location: Osage City, KS Posts: 5,151	Re: Motor Mount Perches? To my knowledge, they aren’t reproduced. What is the worn area you speak of? __________________ TREVOR 1970 CST swb 4x4 (speedwarning,cruise,tilt,tach,8track, original red shoulder belts,tow hooks) 1972 Jimmy (soon to be Hickey cloned) 1971 Cheyenne Super 4x4 swb (tilt,tach,buckets, original blue shoulder belts,am/fm,cruise,tow hooks, dealer 8 track) 1972 Cheyenne Super K20 4x4 Custom Camper (tilt, tach, am/fm, tow hooks, bed toolbox, aux gas tank 1972 Cheyenne Super Crew Cab K30 4x4 Duramax, Allison, np205, buckets, tow hooks (CURRENT PROJECT) http://67-72chevytrucks.com/vboard/s...d.php?t=624819 1989 V3500 Crew Cab (454tbi, NV4500, np205) 1970 Chevelle SS (LS5 454,th400,8track,buckets,tach) :2004 Jeep Wrangler Rubicon (daily driver) WTB: 1968-70 Cruise Control Lever

05-02-2019, 06:57 PM	#8
tj1970cst Registered User Join Date: Mar 2019 Location: Arlington, TN Posts: 170	Re: Motor Mount Perches? The hole on your mount isn't that bad. The big block trucks had a larger hole than the small block trucks.

05-03-2019, 12:10 AM	#9
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? The 71 K20 didn't come with a big block. I believe it was an option on the C models. Supposedly my perches are for the small block 350. I'm thinking there should be a bushing or something to take up the space around the skinny ass bolt that goes through that hole. The other perch is much worse than the one in the photo. I held the new engine mount up to the old perch and it does seem to fit marginally okay, but it sure leaves a lot of room for slop. I would think the GM engineers would have come up with something a little better. That being said I just finished tearing down my NP205 transfer case and rebuilding it. I'm not sure what planet the guy was from who designed that case but clearly no thought was given to rebuilding it. Thanks, Jack

05-04-2019, 10:35 AM	#10
notsolo Registered User Join Date: Apr 2008 Location: Md Posts: 2,461	Re: Motor Mount Perches? These were from a 72 K5 Blazer 350/350...NP205 transfer case.....can post in for sale section if your interested....LMK Attached Images __________________ http://67-72chevytrucks.com/vboard/s...d.php?t=635605

05-04-2019, 10:47 AM	#11
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,028	Re: Motor Mount Perches? It is possible that square body BBC perches were used as they may have junk yard items when your truck was converted. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

05-04-2019, 11:33 AM	#12
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? Anything is possible with this truck.

09-07-2019, 10:13 AM	#13
Jack15T Registered User Join Date: Jun 2018 Location: Sandy, Utah Posts: 102	Re: Motor Mount Perches? NotSolo, Do you still have the perches? Jack



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