Well, to those that have (and haven't)seen some of my recent posts. I am trying to get my engine(350) in my 1970 chevelle. I was having problems with installing it since the previous motor was a 307, so the mounts are wrong. I tried to install the 350 frame mounts, but the holes wouldn't line up. What now?


-Dan

I swapped from my 307 to a 350 without replacing my motor mounts. The motor mounts should be the same for all sb chevy's.

307 are a bastard mount BUT I think they just sit higher. If hood clearence isn't an issue you should be ok using them on the 350.

Make a measurement...between the motor mount ears...should be...2 5/8"....

Measure the center of the hole to the top of the metal base plate...should be 1 3/8".

Some 68-71 chevelles had this problem w/307 and 327 motors.....Yes I know-(all??) chev mounts are the same---NOT TRUE. graemlins/clonk.gif graemlins/waving.gif

Sorry for the center measurement of the hole..should be the center measurement to the bottom of the mount....to much smoke in CA... graemlins/thumbsup.gif

Ok, I have read your guys posts and thanks for them, but still I can't get the motor in graemlins/angry.gif . I tried to bolt up the 350 frame mounts(mounting brackets) but the holes wouldn't line up graemlins/angry.gif unless I am suppose to use different holes other than where the 307 ones were. On the driver's side, I can get the top two holes to line up and bolted in(a friend of mine told me that I only needed two bolts in) and on the passenger side, I can't get the top two holes to line up. If worse comes to worse, I'll just get out my drill. :mad:


-Dan

The 307 is an oddball as far as motor mounts go. To install a 350, you have to use 350 frame mounts and 350 motor mounts. You can bolt 307 motor mounts to a 350 and install the 350 that way, but I'm told the 307 mount is a much weaker mount.

I know that, but I am saying that the frame mounts wont bolt onto the frame for some odd reason.

Just use the mounts that came off the frame

You do not have the correct 350 frame mounts.

If you get the correct 350 frame mounts, they will be a direct bolt in.


Nate

wow lots of stuff here. First off the 307 and 350 frame/engine mounts are different but as long as they are used in sets there is no difference. 307 engine mounts with 307 frame mounts work the same as 350 engine mounts with 350 frame mounts. You could have just put the 307 engine mounts on the 350 and used the 307 frame mounts. There are 307 engine mounts made with the interlocking style so no strength difference between the sets. Next both sets of frame mounts use the same holes. If your 350 frame mounts do not line up with the holes then you have the wrong frame mounts, probably off another chevy but not a chevelle. Double check that you have the correct mounts.

it's not a Chevelle, but in my Nova, i have my 355 sitting on the stock 307 frame stands with interlocking replacement 307 engine mounts, and it works perfect. the mounts ARE the same- hell, you COULD put a big block in the 307 mount setup, or even an old "W" engine like a 348 or 409. headers might be an issue, however.
put the 307 stands back on, get new interlocking 307 engines mounts- maybe aftermarket poly mounts if you are worried about strength- and return the "350" stuff to wherever you got it.

Dan,

Just curious - on the new frame mounts you are trying to install - what are the part numbers - I beleive, not sure as I have to check mine at home, they should end in 611 and 612, hvae you tryed reversing them - ie pass side on driver side - check the mount numbers you have. Let me know.

Rich

I had a 71 Nova with 307 that I bought as a one-owner, 72,000 mile original. I later installed a 350, and then a 454, without changing the original frame mounts. I used the original 307 frame AND engine mounts on the 350. I did use 396 Camaro engine mounts to install the 454, but still kept the 307 frame mounts. They mated up just fine.

Well I had a 69 chevelle 307 PG and pulled the 307 and installed a 396 with same frame mounts, then before I sold the car I pulled the 396 and installed a 350 on the same mounts so I dont believe there is a difference between the 350 and 307 mounts the blocks are the same external dimension why would the mounts be different? Just a thought

Oddly enough the mounts are different - the 307 mounts sit higher, everything else should be the same.

Rich

THANK YOU RICH !!!!!

That's what I tried to tell him in my post.

I had a 307 car, pulled it and installed an L-78 396 but had to use 350 engine AND frame mounts beacause the 307 mounts set the engine up against the hood even with the correct drop down air cleaner. Oh everthing bolted up on the engine and the frame ok, it's just that like Rich said there TALLER..........

He must be using mounts from a different GM or may just have them spun around , because like others have said here, they SHOULD bolt to the frame.... Do the search

LOL the 307 mounts are taller, but with the 307 engine mount the engine doesnt sit up any higher. Done plenty of 307 to SB/BB swaps, in fact just pulled a 396 out I did on 307 mounts, did fine for 5+ years of abuse on stock rubber 307 pieces. The only way an engine is going to sit higher is if you jam 350 engine mounts on a taller and wider 307 frame mount.

Thanks everyone for your replies, unfortnately I haven't had enough time to try all of your advice, hopefully here in the next day or two, I'll be able to, so I'll reply back and tell you all how it goes.