TrendSetter

I have a 2002 awd silverado i just took the 5.3 out and traded for a mkiv bbc.
Does anyone know any info on the motor mounts used for the 4.3 or 8100 in these years? i couldnt find any mention anywhere that the 4.3 blocks changed mount pattern from the original 3 bolt pattern. The pictures of new mounts on rock auto look the same as a 5.3 (4 bolt block side) but its a different part number. I did this swap on a 95 4.3 truck a while back and it was bolt-in.
Id like to use some form of stock mounts instead of fab from scratch if possible. I havent found much info online, but will be heading to the junkyard soon for some hands-on research.

would appreciate anyones feedback on this.

RedXray

Us guys that did the V6 to V8 found out the V8 mounts are different between the 2wd, 4wd and awd. Looking at wholesalegmpartsonline catalog it shows the V6 mount fits all the crossmembers (2wd 4wd, awd). My guess is the 4.3 mounts will bolt to all frames and has the 3 bolt pattern.

These are the old mounts from my 4.3 2000 Sierra



Screenshot from wholesalegmpartsonline catalog showing the V6 mounts fit 2wd, 4wd and awd frames.

TrendSetter

thanks for the info. those parts look like the frame and motor side but is there a third piece that bolts to the block? it looks like part #1 in your diagram is an adapter plate?

1FastBrick

iTrader: (17)

The frames are different between the torsion bar suspension and coil spring. As a result the bolt on frame mounts are also different.

AWD and 4x4 trucks use the same torsion bar suspension the SUV's used.

There is not alot of documentation on the 8.1L but I believe it would mount up to the 1/2 ton torsion style frame mounts. The engine motor mounts don't change for a 6.0 between 1/2 ton and 3/4 ton applications so I believe the 8.1 would be similar even though it was a 3/4 and 1 ton specific application.

That being said, The 8.1L gen 7 BBC doesn't share much of anything with the earlier generation's BBC.

If your on facebook, there are a few 8.1L specific pages. those guys may be better able to help.
The only other person on here Is xx ED xx Edward Cross that swaped the 8.1Ls in to 1/2 tons. He may be able to show or tell you how he bolted the 8.1L in and it may give you a better idea of what your in for even though you want to use an earlier Generation BBC...

https://www.performancetrucks.net/fo...ntures-517282/