Author Topic: 1991 Crew Cab Going 6.0 LS  (Read 9828 times)

Online roundhouse

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1991 Crew Cab Going 6.0 LS
« Reply #15 on: December 27, 2016, 12:20:09 PM »
We used some industrial anchor pads for HVAC air handlers

One inch rubber with a metal plate sandwiched in the middle
Was just something we had laying around and looked batter than a stack of washers

https://www.zoro.com/mason-vibration-isolation-pad-4x4x1-14-in-2lvp1/i/G2279121/?gclid=CLC608T-lNECFUw9gQodWogH8Q&gclsrc=aw.ds


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« Last Edit: December 27, 2016, 12:22:46 PM by roundhouse »

Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #16 on: January 01, 2017, 03:26:48 PM »
Having some minor issues getting my engine mounts figured out. I have the Advance Adapters brackets through Off Road Design. First...the bracket hits the harness ground bolt on the Driver's side. It is a minor issue, but what do you guys do with that ground bolt? Sandwich it between the adapter and motor mount?

Second...I had planned on using my stock Chevy Truck Clam-shell mounts, but the clam-shell is hitting the oil cooler lines on the driver's side! Anyone have experience with this?

Should I be using some other set of mounts that will give me better clearance?! I could totally redo the oil-cooler lines, but I am trying to avoid that. The factory routing is pretty sano.  I would like to use the factory block and hard-lines up the side of the engine.

What mounts have you guys used?  Also...I hear that perhaps the stock location for the bellhousing mount might be tight?  Passenger's side head is flush with the bellhousing flange!  Does the rear coil interfer with the A/C box?  Who can verify some of this stuff?
« Last Edit: January 03, 2017, 07:36:46 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #17 on: January 08, 2017, 02:54:47 PM »
I have not executed a 4x4 swap, but the room on both sides should be the same.  Have you called Advanced or ORD and see what they said?
Sounds like the engine is set back to far.  Find out the plate PN.  I used the standard SBC location with S&P plates but several people make them.

Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #18 on: January 08, 2017, 06:37:26 PM »
I measured the mounting points and the locations for the adapters was in the correct location to put the back of the engine in the stock location.  I ordered another set of mounts and am waiting for them to show up.  They look like they will work a lot better than the standard adapter plates.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #19 on: January 17, 2017, 10:08:21 AM »
So I hit another snag.  Argh!!!

Anyone know the mounting dimensional differences between the SBC and the BBC clam shell mounts?

Apparently these conversion mounts I bought were designed around the SBC clam shell mounts in a 1985 K10.  I was not aware of, until last night that there is an actual difference in the frame side mounting between the SBC and the BBC.  My BBC mounts use a triangular 3 bolt mounting pattern to the frame vs. the SBC 3 bolt mounting pattern that is more like an "L"-shape.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #20 on: January 17, 2017, 12:51:19 PM »
All of them mount the same on the frame.  The shell on 454 is taller.  But the holes are identical.   I have put a BBC in the SBC place with the same mounts.  Yours probably will be different though because it is a 1 ton but the shelf should be the same.  Just a cross bolt.  Got a pic.  Rushing this post

Chris Lucas
73-87chevytrucks.com
squarebody.biz


Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #21 on: January 18, 2017, 09:11:29 AM »
The mounting pattern is not the same!
SBC mount is a 4 bolt-hole pattern that they only use 3 bolts.
BBC mount is a 3 bolt-hole pattern.

Here is a sketch of the SBC mount:


Here is a sketch of the BBC mount:


Here is an overlay of the two so you can see how that one bolt just doesn't line up!


Here is a picture of the two clam shell engine mounts side-by-side:
« Last Edit: January 18, 2017, 09:20:12 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #22 on: January 18, 2017, 12:59:38 PM »
Ah you mean the frame side...  definitely different.
Your 1 Ton is different than a 1/2 also.


Chris Lucas
73-87chevytrucks.com
squarebody.biz
« Last Edit: January 18, 2017, 01:01:37 PM by Captkaos »

Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #23 on: January 23, 2017, 10:21:24 AM »
Confirmed the low-mount LS A/C Compressor isn't going to fit!  :-[

The back of the compressor interferes with the frame stands for the motor mounts, but if I hacked them up about an inch and moved that motor mount back some, I think it would work!  The only problem is that I am trying to avoid permanent modifications to the truck that can't be reversed.  Why?...I don't know...just wanting to keep it so that I could easily put a Big Block back in it if I want to.  I have access to my work fab shop, so within reason I can make just about anything I can design.

I may look to designing a new bolt-in Passenger's side mount in the future to get that A/C pump back in there, but for now I am gonna cap off the A/C system and possibly buy a high mount kit in the future.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #24 on: January 24, 2017, 11:49:09 AM »
Take a pic.  Of it in there.  IF you can run the factory setup, I would.  I plan to change mine and put the AC low.

Chris Lucas
73-87chevytrucks.com
squarebody.biz


Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #25 on: January 30, 2017, 07:35:49 AM »
What do you guys do for vacuum to the heater?  I have Hydroboost for the brakes so no need to worry about a big vacuum line.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #26 on: February 01, 2017, 04:15:21 PM »
Tee off the factory vacuum port on the truck intake.

Chris Lucas
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squarebody.biz


Online ehjorten

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #27 on: February 01, 2017, 04:18:44 PM »
Is that the big push-to-connect fitting at the back of the intake, or the one that is molded shut on the RH side of intake up under the trim cover?  If it is the big push-to-connect one, what fittings are available?  Mine from the 2004 just has a plug fitting in it.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline frotosride

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #28 on: February 01, 2017, 04:55:07 PM »
also on the passenger side of the manifold there is often a vacuum  port that still has the plastic break off cat attached and can simply be snipped off.
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Online Captkaos

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Re: 1991 Crew Cab Going 6.0 LS
« Reply #29 on: February 01, 2017, 04:56:23 PM »
The one on the passenger side of the manifold if I remember right.  It  should be the right size.

Chris Lucas
73-87chevytrucks.com
squarebody.biz