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Big Block Motor Mounts? The difference between two wheel drive and four wheel drive!

max 02

max 02

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When we put the 454 in my 77 there was one thing I never liked.

The oil pan rests on the cross member... I mean not even a piece of paper will fit in between them.

Is there a difference between BB and SB mounts, Didn't think there was?
How can you tell if the mounts are still good? They seem to be.

When it took the old 305 out it had plates in between the block and motor mounts, those plates had rods bolted to them that went back to the th400 on both sides.

I wanted to maybe put those back in I think they were 3/8 thick...spent all day looking for them but I cant find them or the rods. Maybe I gave them to Russell when he bought my 400. :dunno:

Anyone else has this problem? What would be a good way to get some more clearance? I don`t want to rub a hole in the pan! :doah:
 
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Those plates are only maybe 3/16" thick at most...maybe you can make some thicker ones from flat stock to shim out the clamshells?..

I know 4x4 trucks had taller clamshells on the engine compared to car or 2wd ones,the mount bolt holes are about 1" further away from the engine on 4x4 mounts..maybe thats part of your issue--I tried using car clamshells and the engine nosed down at the front and the balancer was very close to rubbing the crossmember--I ran it that way for a week till I found a pair of 4x4 clamshells to put on it..(and it sucked doing it with the engine in place!)..
 
Yeah you are right, 3/16s! :doah:

I didn't know there were different clamshells for 4x4. Although I used the ones that were on the old motor. :dunno:

And yes Rob...whatever I do it IS going to suck!

I`ll have to do some measuring buddy has a 454 out of a 4x4 suburban sitting in his shop...hopefully still has the mounts on it. :D

Actually could you get a 4x4 sub with a 454 factory? This one was 4 speed too.
 
If your using the stock rubber mounts they sag with the big block pretty bad.

Here are some pics of my BBC mounts





oldmount_zps9235b18d.jpg


With the poly the motor lifted up where it should be

newpolyinsert_zps9c07ca15.jpg
 
I put brand new ac delco motor mounts in with my 408 a few years ago... One is completely blown out and the clam shell is laying metal on metal :doah:

Id say thats how you tell if they are shot though :whistle:

Its actually bulging rubber out the side.
 
skunked said:
If your using the stock rubber mounts they sag with the big block pretty bad.

Here are some pics of my BBC mounts





oldmount_zps9235b18d.jpg


With the poly the motor lifted up where it should be

newpolyinsert_zps9c07ca15.jpg
Click to expand...

Poly mounts look a lot better for sure!
Deuling said:
I put brand new ac delco motor mounts in with my 408 a few years ago... One is completely blown out and the clam shell is laying metal on metal :doah:

Id say thats how you tell if they are shot though :whistle:

Its actually bulging rubber out the side.
Click to expand...

Mine still look good. But they are more than likely from 1980! :haha:

Just realized I posted this in the wrong section. :doah: I asked Greg if he could move it for me. :popcorn:
 
max 02 said:
Poly mounts look a lot better for sure!


Mine still look good. But they are more than likely from 1980! :haha:

Just realized I posted this in the wrong section. :doah: I asked Greg if he could move it for me. :popcorn:
Click to expand...

Wondering how long till you noticed :whistle::haha:

I'd say some new mounts or shim it up....or high clearance crossmember time :whistle:
 
Yep, just confirming that 2wd mounts sit lower/shorter than 4wd mounts.
 
The engine brackets,are what I was calling "clamshells"...the motor mount thru bolt hole on 4x4 ones are 1" or so further away from the block,which lifts the engine up that much more away from the crossmember..

If you cant find any,you probably could just weld flat stock over the existing holes in the brackets and drill new holes an inch further down...
 
diesel4me said:
The engine brackets,are what I was calling "clamshells"...the motor mount thru bolt hole on 4x4 ones are 1" or so further away from the block,which lifts the engine up that much more away from the crossmember..

If you cant find any,you probably could just weld flat stock over the existing holes in the brackets and drill new holes an inch further down...
Click to expand...

I thought so but wanted to make sure.
Now with a bunch of measuring I got a set on my bench that are for sure 1/2 inch taller than the ones in the truck! :haha:

How retarded it that! :doah:
 
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It is the little details like this that makes swapping engines "fun",huh?..:surepal:...especially after you dont notice it until it is all bolted in,just when you thought you were "done"...:doah:..
 
max 02 said:
Is it just the mount that bolts to the cross member with the rubber/poly insert that is taller, or the piece that bolts to the block of the engine?
Click to expand...

Clam shell as mentioned.
 
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