Looks like Friday I'll be getting my 455. Verified the block number tonight to be sure it's a 455. Guy said it has "G" heads. Being that it's supposed to be a complete, original running 455, that would make it a '71 motor. (Only year for "G" heads.
Are the "G" heads good? I know, I know, as long as they aren't "J" heads.. But where do these fall in line in order of most desirable to least. I think I read something somewhere about hardened seats?
Can I use the same motor mounts as my 350 or do I need different ones?
I plan on doing some mild work on the motor, nothing too crazy, I'm not rich. Backed up by an olds TH400 and a posi.
Motor wise, I'm thinking flat top pistons to raise the compression a little (maybe shave the deck slightly too) intake, carb, headers with 40 series flow masters and some street cams. Just wake it up a little. Might take me a while because $ is tight but it'll get done eventually.
Your thoughts??

 

motor mounts and frame mounts are different from 350 to 455.

 

Don't want to sound dumb but I'd be dumb if I didn't ask what you mean by "frame mounts"?
Secondly, where could I find these items that I'm going to need? Would any mounts that were under a 455 work or do I need to stay within the 68-72 range for my 72 cutlass?
How about one from a big block 72 Monte Carlo perhaps?

 

The 350 mounts will work fine. If you replace just the mounts order 350 ones. The mounts and frame pads work as a set. Just don't mix and match, i.e. 455 mounts on 350 frame pads or vise versa.

 

Monte Carlo? NO

 

The mounts bolt to the block and the frame pads. Frame pads bolt to the frame and engine mounts

 

the G heads are virtually the same as C heads maybe slightly better flow if your lucky. they do not have hardened seats. only the heads with a small A after the large letter designation, GA would be hardened seats. they have 80.0cc chambers. olds varied the dish in the pistons to change compression and flat tops would yield 11-1 or more depending on deck height and head gasket thickness and won't run on pump gas for sure so you better decide what you are going to use it for primarily before you buy parts. 8.5-1 should do well with pump gas above that you may have to find higher octane fuel. the 11-1 engine seems to like 112 race fuel.

 

Oh, I guess in my mind I always just thought of the whole thing as a motor mount. So, I got 1 person saying that I can't use the ones in my car and one person saying I can. What's the true answer? Can I pull that 350 out and drop that 455 in or do I need to change the mounts? I would think they'd be the same but I'm not 100% sure so that's why I posed the question. Can anyone else verify? Maybe someone will chime in and say "yeah, I've done that swap and it's a bolt in; drops right in, no changes necessary". Bueller? Bueller?

 

Use the 350 frame mounts and motor mounts, new motor mounts if yours are old because they will start sagging. Also the big block is heavier and has more torque so it may break old mounts.

 

Ok, apparently my answer isn't good enough, how about this. I HAVE a 455 on 350 mounts and pads from a '71 in a '67 Cutlass. Works perfect, been in the car since '02, ran 12.44 at 113 on street tires. I have a '77 403 on '70 Cutlass mounts and pads in 72 Skylark. I'm a professional tech of 21 yrs, and an Olds guy for 27. That's your true answer. Just for the record the constant wrong info on Olds mounts gets under my skin. That and the "these headers fit Cutlass but not Supreme"

 

Nate, don't take offense, I just like to be 100% sure. I had gotten 2 different answers so you can't blame me there. And I deal with these types of things on one of my other forums where people give advice on stuff that they have never even done. I really don't want to hear from someone who truly doesn't know because they never did it. They just regurgitate stuff they read online which could very well be bad info. I don't mind if someone says: "I've never personally done this or that but I think ..... Or I've read....." Then that's being fair about their real experiences. I appreciate ALL input/opinions from very experienced people to beginners. That's what feeds the conversation. That's how people learn or come up with new thoughts/ideas. So bottom line is that my small block mounts will work with my big block but it's recommended that I get NEW motor mounts because mine are old (most likely original) and the motor mounts need to match the frame mounts. BBO--->BBO or SBO--->SBO

 

Gas tank came today! The middle vent is like 4 inches over from the original vent's position. The filler neck looks a little off. Looks like it's a bit off to the side from where the original was. Might have to fix that before installing but I still need to get sending unit and new straps anyway so I have time.
The 455 will be here in a couple hours. 😊