Since I pulled my motor now is the time to change my frame pads and motor mounts to the big block setup. I ordered the new parts but haven't removed the old frame pads as yet. My question: what ever hardware that is holding the small block frame pads in place, can I use it for the big block frame pads or will I need different hardware (in my buick swap I had to get new hardware). If I do have to get new hardware can someone give me a heads up on what I specifically need, bolts size, thread count etc. so that I may get everything in advance (I'm bumming rides right now so cant really run out in the middle of the swap). Car is a 70 cutlass with 455 by the way. Thanks. Allen allioop108@aol.com
You don't need to change motor mounts to switch from a small block to a big block. The frame pads and the rubber mounts must be matched together or your engine will sit kinda funny in your car. Big Block mounts that came out in 1969 were more of a GM corporate directive to all divisions to fix a Chevy problem. When an Olds loses a mount (rubber pulls loose from the inner steel reinforcement) the engine won't drop, but may come up a little. What was going on with the Chevies was when they lost a mount, it dropped down. That was a real problem with a fixed throttle linkage system as used on all corporate up through 1967. In 1968, they went to a cable system, and throttle control wasn't an issue. By the time they resolved it, the hornets were flying, each division was tyring to outdo each other in a pissing contest, so the corporate edict came out that everyone needed reinforced mounts. The major recall fix at the time was to add a pice of chain or cable to restrict the engine from falling down on the Chevies. The Olds change required incorporation of an inner sleeve around the through bolt rather than just drilled holes in the sides of the frame mount. That required that they raise the center line of the pivot bolt about 3/8 inch to get it in. The rubber mounts for them also were changed to accommodate that. If you mix the two (all small block and pre 1968 big block mounts vs 1969 and newer big block mounts, the engine will either sit high, or you won't get the pivot bolts in. Best advice is to leave the small block frame pads as they are in the frame, and if you buy new mounts, match them up with your old ones to see f they sit the same way. Most of the parts books are all screwed up on this at the auto parts stores. :bglasses:
Hi Dave H, This is no longer a conversion, car has been on road for 2 years now and I cracked the oil pan on saturday so had to pull motor to change pan. No I'm not going to mix and match, I already ordered new frame pads and new motor mounts all for the 455 motor. I was reading this post http://www.v8buick.com/showthread.php?t=99327 and decided to make the change for this reason: Why the difference? The big-block mounts are not just a chunk of rubber. Rather, they are interlocking so that the rubber of the left mount is actually in compression instead of tension. Even if the rubber fails, the mount will not separate and the engine will not lift. If it were me, I'd make the effort to switch to big-block mounts. Every 350-powered Olds I've owned has broken the left mount eventually, despite the fact they were mere daily drivers. Yet my 455-powered W-30, which sees plenty of wide-open throttle operation on street and strip, has never broken a mount. plus I want the car to be as big block correct as possible. Since the stuff is in transit I need to see what to do about hardware so that I won't have to run out when all my tools are laying in the street. Yes I currently have small block frame mounts and small block motor mounts. I just read on year one site to use same hardware but want to verify as I have a lot to do and very little time, I'm without a car till this is done. Car is a warmed over big block with a stick shift, I dont want to beat on it and have the motor jump up through the factory original OAI hood. Allen allioop108@aol.com
No problem. If you're going to spend the money on new ones, might as well get th right ones. Lots of people mix them up and then wonder why the valve covers hit the power brake booster and/pr A/C Evap Case (if so equipped). Don't think I've ever heard of one where the engine actually rises up out of the mounts, but OK. Just see a lot of cracked ones. All the hardware (bolts, nuts, washers) on both the 6 pad to frame bolts and the bolts and nuts that go through the pads and engine mount are the same if that's your question. You will not be happy trying to fish new pad to frame bolts up through the front crossmember with the front suspension in place. Also suggest you pay close attention (take a picture) to which set of holes were used to mount the pads to the frame. There are three sets fot the various engine combinations that were available in A bodies in 68-72.
youre creating work for yourself not even needing done. since it was originally a 350 car,just buy some new 350 mounts,and youre done.
Yes they were new 350 mounts, thing is when I do a clone I like to do it all the correct way, even stuff you will not see, like the correct floor hump I have installed. Its just the way I am. I hate when I see on ebay a gs clone for sale and the only thing gs about the car is the hood. But anyways, I got my new frame mounts installed and they do use the old hardware as year one stated which was basically a nut and bolt 9/16" head, probably the same one used for the tranny cross member to chasis mounting. I will tell you this though, it was a lot easier to do then when I changed my buick mounts to the big block ones since the frame lays on the chasis, the bolt drops through it and into the front cross member and then you just catch the nut and tighten, plus I was able to really get in there since the lower control arms were off. I would say it took 10 minutes each side. I put locktite on the bolts since about 3 of them were lose enough to just spin around. And if in the end it wasn't necessary I at least have peace of mind. Allen allioop108@aol.com
Washers? I didn't see any washers and wanted to put some on but had none in the garage. 3 of them were lose enough to spin but not come off, not with all the dirt and grime on the hardware. I did put locktite to secure the nuts and bolts though. The good thing with locating them was with 36 years of dirt, there was basically an image of were the pads should sit, even after I scraped off as much grime as possible. Allen allioop108@aol.com
i believe the frame mounts and motor mounts are the same wether its a 350 or 455 on an olds . ive replaced a few 350 's with a 455 's and they drop right in
NOPE, big difference, frame pad is longer and so is motor mount. yes either big block / small block will drop right in but if you look at the frame mounts you will see 350 is tiny compared to 455 one and ditto for motor mount. And yes I looked since I did the change over and wanted to know if I wasted my money. 455 set up is beefier and low and behold everyone, my 350 motor mount was in the process of splitting apart. If I wasn't changing stuff, oil pan, new mounts I might not have noticed this until something happened down the road, now I have peace of mind. Allen allioop108@aol.com
YUP, scared another one. Way to go! :beer :beer BTW, 65-68 442's used the small pads on the frame with a reinforced motor mount. Never a problem there. But, hey, when Mother General says you gotta problem, buy! Stand up salute and say "Thank you, sir, may I have another". And all is well in Central Office........but we still don't like those crude, rude hillbillies in Lansing............WE"LL GET EM EVENTUALLY! EVEN if we take down the Empire! Bring on Saturn!!!!!!!!!! Achievas and Aleros for everybody!!!!!!!!!!! Now there's peace in the valley. All we gotta worry about now is how do we buy off 40,000 union people at $100-$150k per pop.... Ah, we'll worry about that tomorrow! Let's go to the gym, then get some quiche! EEEEEEHAHHHHHHHHH!!!!!!!!!!!!!!!!! :TU: :TU: :TU: :TU: :beer :beer :beer :beer
I have them but can't figure out how or where they go, someone please send me a pic of how to attach these pieces. I tried looking in chassis manual but still no good, I need actual pic. Allen allioop108@aol.com
The run from the center of the upper inner fender reinforcement in the hood hinge attachment area down between the cowl sides and the rear inner fender reinforcement and attach at the bottom of the cowl weld lip near the lower fender mounting bolts. You can see them in the assembly manuals, but will probably take actual photos of them on a real car if you can find someone with a real car. Think you need to get out your drill. :bglasses:
Yes pics please, I was originally going by the assembly manual and as a result the braces are still in a box in the basement, couldnt make sense of what to do. Allen allioop108@aol.com
Try posting on www.Realoldspower.com. There's lots of OCA people there now and I'm sure someone has an original SX car or 442 with those braces.
