olds 307 and 403

Curious if they will drop a 455 enough to use my Sanderson headers? I had a set when I bought the car, thought they were junk as I didn't realize they were a lower profile clamshell design. Anyone have a set?

joe_padavano

Which "mounts"? The rubber mounts for G-body cars are the same 2328 mounts as used on BBOs since 1969 (and on all Olds motors since 1973). And as always, the crank centerline is in the SAME place relative to the motor mount bolt holds on ALL 1964-1990 Olds V8s. Given the lack of space between the oil pan and the crossmember, you CAN'T "drop" a BBO any more than the stock crank centerline location.

olds 307 and 403

Joe; I am no expert on the 455. Do they all have the lower profile mount? The SBO G body mounts looked different but it has been years since they were in hand. The idea of swapping motors and trans a bunch of times isn't appealing. I hate immobile vehicles but a 260 and a dying TH350 isn't appealing either.

joe_padavano

NONE of them had a "lower profile mount". Read this thread.

olds 307 and 403

Maybe my mounts were wasted, they were almost a two piece clamshell mount. What the heck is the difference between the 2261 and the 2238? Tells me this is probably a no go and not worth the frustration.

joe_padavano

One more time. You can remove the mounts completely and the engine won't go any lower because of the clearance between the crossmember and the oil pan. And when you do finally read the link I provided above, you'll find that the rubber mounts MUST MATCH THE FRAME PADS, not the block.

Sorry, but I've typed this dozens of times in the last couple of years, and I documented the info in the link I provided you.

EVERY SINGLE 1964-1990 OLDS V8 has the motor mount bolt holes in exactly the same place relative to the crank centerline. The motor mounts and frame pads work as a matched set, and they put the crank centerline in the same place. Since the frame pads sit on a crossmember at an angle, if you use the incorrect rubber mounts, not only do the holes that bolt to the frame pads move vertically, they also move horizontally and thus won't line up. I don't know what you are trying to accomplish here. Even if you cut the crossmember to allow the oil pan to drop down, the BBO heads and thus exhaust ports are STILL wider than on the SBO, so the SBO headers still don't line up. I don't know how to make this any clearer.

olds 307 and 403

I oviously searched incorrectly in the forum. Yes, I did read it and ofcourse the pics Summit showed the back side of the mount. So it was clear as mud what as hell the actual difference was. Did the 80's Tornado have different mounts? Supposedly the 307 in my 88 came out of a 83 Tornado. Maybe I just broke the mounts when I pulled out the 307. Either way I can drive around sounding cool, just better not race anyone.

joe_padavano

Toro mounts are completely different and can't be used in a RWD car.

olds 307 and 403

Thanks, did not need to be looked down on. I had a shitty week last week with my dog of nearly 15 years died and now making 10 grand less a year doing the same job, actually more. Today I backed into a truck with the work truck, 6 points off my 1A license. There were nearly zero Olds of that era around when I was younger, so nothing to compare to and never seen in person. I am not the only one who thought G body cars had different mounts, I guess mine were just plain shot.

joe_padavano

I'm sorry about your dog and I realize stuff happens, but geeze, I (and others) have been writing this same info about motor mounts on this site for a decade now. I took the time to document that info in a sticky. More to the point, if someone takes the time to bend down and look at the clearance between the oil pan and the crossmember, it becomes obvious that the motor cannot be lowered any more in the chassis that it already is.

olds 307 and 403

I realize there is only so far it will drop, sorry I dumped on you. Either way it could quickly turn into $1000, too much for me right now. I need a good radiator, drive shaft shortening and a yoke to run the 455/TH400 minimum plus possible exhaust issues. I will stick to my orginal plan and finish the 424 SBO eventually and rebuild the BOP TH350 armed for bear. Next year I can go to cheap antique plates on it for a whole $120 all year. There will be Sanderson Shorty headers, 2.5" X pipe dual exhaust and 3.42 gears behind the mighty 260, should help even more, although the exhaust is too much.

Kennybill

The Firebird/Seville/Omega were a clamshell type but no lower than the "normal" frame mount/motor mount.

joe_padavano

Firebirds and Sevilles with Olds motors (and the 1977-1990 Fleetwood with 307) used the Chevy-style "clamshell" rubber frame mounts with the metal brackets on the block. The Omegas used conventional Olds 2328 motor mounts and metal frame brackets. As noted, you still can't lower the motor any further.

olds 307 and 403

I used the Firebird mounts on the 94 4x4, they weren't plug and play for that app, too much space that needed spacers to fill.