Swapping DOHC for 3X00

[jmgtp]

Lorenzo,
thanks that is a lot of useful info - I will be referencing that as I collect parts. I picked up a alternator and alternator bracket from a 97 3100 lumina today.

I wonder if the a/c mount from the dohc can be reused? or will it have to be 3x00 specific.

some mild progress, well not really, just got the engine mounted up to the stand. I'm waiting on the intake gaskets before I start pulling it apart...

[pocket-rocket]

IMHO, Lorenzo has to be pretty much the most knowledgeable person when it comes to W bodies and their drivetrains that I know. When it comes to something related to one, I would take his comments/advice before I would a GM certified tech because of his experience with them vs the techs.

[bszopi]

Where is Taylor when we need him? I am pretty sure he has already done this swap, so he would probably be another very valuable resource.

[gpse3400]

Lorenzo,
thanks that is a lot of useful info - I will be referencing that as I collect parts. I picked up a alternator and alternator bracket from a 97 3100 lumina today.

I wonder if the a/c mount from the dohc can be reused? or will it have to be 3x00 specific.

some mild progress, well not really, just got the engine mounted up to the stand. I'm waiting on the intake gaskets before I start pulling it apart...

No problem Sir. The AC bracket cannot be used, you will need an AC bracket from a '91-'95 pushrod w body. Also you will need the lower main mount bracket from a w body as well.. If you can still get them from GM( I dont see why not) they are super cheap, maybe $15.

[gpse3400]

IMHO, Lorenzo has to be pretty much the most knowledgeable person when it comes to W bodies and their drivetrains that I know. When it comes to something related to one, I would take his comments/advice before I would a GM certified tech because of his experience with them vs the techs.

Thanks man, most appreciated! I might just finally make Technician my profession once and for all.

[gpse3400]

Where is Taylor when we need him? I am pretty sure he has already done this swap, so he would probably be another very valuable resource.

You could ask him questions and he will not steer you wrong with mixing and matching GEN 3 parts, mpfi3100. Though he did learn through me.

But mainly Chris was the pioneer in all of this.

[pocket-rocket]

But Chris hardly posts, just like Taylor

[jmgtp]

No problem Sir. The AC bracket cannot be used, you will need an AC bracket from a '91-'95 pushrod w body. Also you will need the lower main mount bracket from a w body as well.. If you can still get them from GM( I dont see why not) they are super cheap, maybe $15.

Ok added to the list:
-91-95 PUSHROD AC Mount (doesnt matter if it is 3.1 MPFI or 3100 SFI?)

As far as the lower main mount bracket from a W car... is this also pushrod specific or will the hardware off my dohc suffice? I always thought the Gen I W cars used the same motor mounts across the board at least as far as mounting and physical shape (i know some had liquid filled, others solid etc).

Will either of the mounts on my DOHC work (front or rear)? I'm sure I cannot use my dohc dogbone mount since the bracket bolts to the head. Will any W car 3x00 dogbone brackets and dogbones work?

I am glad you found this thread!

[pocket-rocket]

You could run through one of the parts store sites and see if the engine mount part numbers are the same. That would tell you if they are the same across the board.

[gpse3400]

Ok added to the list:
-91-95 PUSHROD AC Mount (doesnt matter if it is 3.1 MPFI or 3100 SFI?)

As far as the lower main mount bracket from a W car... is this also pushrod specific or will the hardware off my dohc suffice? I always thought the Gen I W cars used the same motor mounts across the board at least as far as mounting and physical shape (i know some had liquid filled, others solid etc).

Will either of the mounts on my DOHC work (front or rear)? I'm sure I cannot use my dohc dogbone mount since the bracket bolts to the head. Will any W car 3x00 dogbone brackets and dogbones work?

I am glad you found this thread!

A/C Bracket can be either or.

The TDC uses 2 lower mounts while the push rod engines use one. You will need to use the push rod mount but in conjunction you can also use the tdc rear lower mount. The dog bones have to be from a pushrod

[jmgtp]

I checked the autozone site to see what the pushrod mount looks like:

The LX9 has a plate bolted to it that runs beneath the crank pulley... would this be the correct location for this mount to bolt up? I don't recall seeing a place for this mount to bolt up to on my subframe... is it there and I never noticed it?

it is only ~$40 but I don't know if I trust a motor mount from Autozone.

[robertisaar]

is it a hydraulic or solid mount? their solids aren't bad but the hydraulics are kind of iffy...

[pocket-rocket]

I checked the autozone site to see what the pushrod mount looks like:

That mount sits in the "bucket" by the crank pulley that is in the subframe now. It looks a lot like the ones on the 3x00 minivans, except they have 3 places to mount to the engine. One front, one side (same axis as the crank) and one in the back.

[gpse3400]

Yeah Jon you are right. But the 3 piont mounting is due to the plate that is attached to te top of that mount of which you can get from the stealer or a junked car. All GEN 3 w bodies 1st and 2nd generation will have this. As mentioned, I also recommend the solid rubber mount as well, you can get that from NAPAonline.com. If you use pushrod main lower mount and the TDC rear mount and the pushrod torque strut, you will have VERY little movement in the driveline. Most of the wheel hop will be eliminated.

[jmgtp]

All great info, thanks guys.
I'm not sure if the AZ one is solid or hydraulic. I will price hunt for a solid mount.

The LX9 already has the mounting plate so I should be good there:


Yes, I do plan on using the dohc rear mount and pushrod main mount. Still gotta pick up the dogbones/brackets - hoping to come across them for cheap on eBay.

What is the word on pulling a 660 with a getrag attached out the top of a W car? If I can pull the two out together it will be easier to separate outside of the car. I guess the same goes for the install of the LX9 and the 'new' 284 - can they go in together?