Hi, this is my first post on the thirdgen board even if I've been a member for a while. Many of your posts have been very useful to read, lets hope I can bring some of my knowledge back to you guys later! ..and with that I don't mean useful tips about polar bears or how to pick up the good looking blondes from where I'm from Sweden... This problem is a bit tricky tough, I've been searching for hours just to see if anyone has came across the same problem, that the engine wont drop down fully on the motor mounts. We've spent hours with bending and trying to get the engine in place but it seems to be impossible. My car is a 82 Firebird, I've swapped engine for 2 times. The first one was a 305, the second a 350, now there's a 383, 4bolted 010 truck block from 73 what I remember.. I don't have the casting # in front of me but as I've understand there should be no external differenses between any of the chevy small block, first gen. With the block mounts installed on the engine I can measure that they are roughly ½ inch to wide compared with the motor mounts on the K member, which now has new polyurethane inserts from energy suspension. I can assure u that the clamp shells and inserts are correctly installed as I've followed the instructions not only one time. When trying to lowering the engine, I can only get one motor mount bolt through. At that time the engine wont get down fullty on the other side. So please, can anyone help me figure this one out. Is there a external difference between the blocks or is there something that I've missed? I'm going to drill up the holes of both the block mounts and clamp shells to make them adjustable on the block and to the K-member. I Hope you get the picture and understand my rough english... When I say "block mounts" I mean the brackets that bolts into the block with 3 bolts and are used to hold the engine in place on the inserts by the long bolt. Don't know if there's any other word for them? Any suggestion of whats wrong? Thanks! / Andreas, Sweden

the halves of the engine mounts that are on the engine are for a f-body right?

the poly inserts for the k-member side have to be installed a certain way. Is it possible they are upside down?

I would not modify the mounts, something is wrong.

Does the engine have the right oilpan? its not hitting the k-member and sitting on it is it?

Not all GM engine mounts are the same. You should be using the mounts that come with a third gen or an equivalent aftermarket mount. The mount that you can currently get the bolt into may be sitting too low.

I was wondering the same thing. Getting ready to install engine into 91 Z28. Engine side mounts are pn 14039436 and 334971. On 334971,it is written 89 tpi lh. I don't remember who I ordered these from(a company I heard of from her I'm sure) Did some searching, 14039436 seems to be a valid pn. 334971 I have no info for. Could you guys tell me if I have the right mounts? Does it matter what side is installed where? They are nearly identical.

I had this same problem when installing my engine with the same motor mounts from energy!!!! The way i got the engine in was, There are 4 tabs coming out of the mounts that are in the way of the engine sitting in the cradle. I took a dremel and cut those tabs off. As soon as i did that the motor went right in. Not sure if this was the correct thing to do but at the time after about 3 hours of trying to figure out what was going on. I didnt really want to take the engine out and take the mounts back off (which is a pain in itself) return them and get a different set. This was the quickest thing I could think of and now the engine is in and I have had no problems!!!!! Maybe that helps you out.

Thanks, this site is awesome, Im impressed by all the quick replies so far.

Yes, the halves of the engine mounts that are on the engine are for a f-body, its the same pieces that have been mounted on the earlier engines without any problem, the part number also seems to match. I found a picture in a service manual, showing a mount with the same number.

The inserts are installed correctly by the manual. You can only bolt them in one specific way to the K-member because there are different spaces between the holes in the mounts.

The oilpan is changed to a chromed moroso, still almost the same external messures, I've already checked and there is space enough for it.

Sounds like an idea, I was thinking about doing the exactly same thing because it feels like the engine would slip in without those tabs from the bushings. What stopped me from taking them away were that I assume they have some kind of function to stabilize the motor mounts. Why would they otherwise be there?

So far, I've started to take the mounts back off from the K-member to drill the holes bigger.. Its a PITA just as you know but I can't find any other way to solve the problem.

Even if I'll get the engine in, I want to figure out what have caused this, as many of us third gen owners have both switched engines and motor mount inserts without any problems.
I'd have hoped that everyone switching to poly inserts had struggled with the same kind of problem.
It may be a good point for other who's about to make changes to observ this issue.

i will still say dont drill anything out. Something is not right somewhere. When you have it apart again, see if the mounts will go together without the engine on them. Make sure something isnt bend or misaligned.

Drilling will come back to haunt you, i guarantee it

//86TA\\
Thanks for the advice, I get your point

Drilling the mounts is the last thing I want to do but here I've spent like 15hours trying the get the engine in place and now the vaccation is over so Its back to work. Everything went fine with installing the new brake components, putting some new paint in engine bay, modifying the coolers place to leave more room for a wider one. Everything went just fine until it was time for putting the engine in place. Well, I found a couple of treads now, when I was looking to another board, think it was this one:
http://www.motorsportsvillage.com/fo...=4097&start=15

That link brougt me back to the thirdgen board and some mount bracket issues of whats left and right. As I've said before, Im sure of the part number, at least one of them, the 039436, I have to check the other one too but it shouldn't really care just to get the engine in place...

I'll post some pictures for you so you can see how close I am. Next thing to do is to compare the new poly inserts with the old ones and see if the center hole lines up as before in the center of the clamp shells. This takes a lot of time to figure out.

so in the first pic, the passengerside mount is together?

is the driverside just hung up on the metal tabs on the poly inserts?

Do you have multiple engine side mounts laying around? i know there is a left and a right, and they are different. Maybe you have 2 of the same one?

Yes you're right, in the first pic, the passengerside mount is fully together, I could even put the bolt thru it. The second picture shows whats left from getting the engine in place, seems just to be the tabs but when I took meassures i found that the space between the center of the bracket mounts were about ½" wider compared with the space between the center of the mounts.

Seems like the brackets should get closer to eachother, further down on the engine block and the mounts would need a bigger distance by moving them up on the k-member. I left all the bolt loose when trying to install the engine so they would adjust but... no...

I'll check the other brackets part number but Im 99 procent sure that isn't the problem because I've noticed they're not fully the same and as I've said earlier, the old 305 and 350 engines went up and down on the old mounts without problem.

Either there's something strange going on with that engine block or there's something wrong with those bushings.. I'll come back with more info after next visit.

I appreciate your interest in trying to figure out whats wrong, sincerely
/ Andreas

I just got some info from the guy who bought my old 355 engine, I asked him to take measurements of the distance between the long bolt holes in the brackets, mounted on the engine.
They seems to match with my measures so that means the only thing that could be wrong is the bushings or the way they are placed in... Its strange because I did exactly what the instruction told me to do.

Either way I got wrong bushings or the clamped shells could be installed in a different way on the k-member. I'll take a look at the box again, I bought a complete kit with the inserts and transmission mount from Summit. Think its this one: http://summitracing.com/parts/ENS-3-1130G/?image=large
3-1130G, Can somebody tell me if this is the right part # for my application? It says:
camaro, firebird 77-92 305cui
firebird, camaro 78-79 350cui
Why dosn't it cover third gen with 350cui? Is it just a miss? It goes with the 350 in 78-79, so whats wrong here?

a 305 and a 350 are identical exteranlly. The mounts are the right ones.

The only thing i could think of is maybe one mount is installed rotated 180 degrees? the front should be in the back, follow?

It could also be an issue caused by you getting one mount on first, then trying to line up the second. Maybe if you put the engine in evenly, both sides going on the mount at the same time, not one first, the mounts will clear the metal tabs in the poly insert. I seem to remember having that problem last time i swapped my engine.

Thanks man, here's what happend:

I made a short visit to the garage and took the motor mounts of the k-member to check the poly inserts again and compare them with the old rubber ones.
When comparing them I could see that the poly inserts are totaly fixed in the clamped shells, the stock ones seems to be able to move up and down in the mounts because they aren't as wide as the shell. So for that reason they might be able to adjust and what mount bracket is on the engine dosn't make a big difference just for geting it in place.
Don't know if the stock inserts are just worn-out and that's what makes them "adjustable" in the mounts or if they're fabricated like that? Maybe someone installed new GM motor mounts could tell?

When comparing the bushings I also found the metal tabs to be different, maybe thats what we could expect with some of those after market stuff
Anyway, That slightly difference may also affect the tolerance, especially when its so important the brackets isn't similar to each other as they should have two different part numbers.

That leads me to the biggest discovery so far;
When comparing the mount brackets I could see they were exactly the same, they both has the 039436... part number so I'll need another mount for one of the sides.
Im surprised this could have such a big impact but I guess that small differance makes it very hard to get the engine down from straight above, so the engine don't hit the metal tabs from the inserts, which as I said before is even more critical when switching to those poly inserts, because they're firm.

I'll give more feed back when I've found a new bracket and the engine is in place, hopefully... It dosn't seems to be all right with the meassures I've recived from the guy who bought my old engine but on the other hand I don't know if he has the right brackets too... I'll find out... Sometimes it can feel really good just to find out whats wrong. Lets hope that's it.

Thanks so far!

I know there's already a couple of treads about those brackets but since I didn't know what was wrong from the begining (still not 100% sure) I think its the best to continue in this tread.

Its something very fishy with the part numbers of the brackets.
I found both left and right bracket att Scoggin-Dickey Parts Center:
http://www.sdpc2000.com/product/10213125/BRACKETE.aspx
http://www.sdpc2000.com/product/14039436/BRACKET.aspx

When I looked at Gmpartsdirect I could only find the left bracket so I asked for the right one and here's the answer:
"The part number you requested has been discontinued and is no longer available from GM. "

When Im talking to the Swedish GM retailers they all say: Its the same bracket for both left and right side.
So can somebody please tell me what's the difference between left and right bracket, is the left bracket a shorter one or has the right one a welded nut because of the bad clearance of the fuel pump?
Is there any difference? Pictures please.
Sorry for being such a PITA but this bracket-mount thing is driving me crazy.

i would have to measure the mounts on my car, but im 99.9% sure they are slightly different.

There is no welded nut on any of them.

Ok, thanks for the reply man! There must be a "slightly" difference if the engine should get in there. One good news so far is that I've found a bracket with part #334970 on a junkyard so during the next weekend I'll be able to try again.

I would have hoped that the difference should look something like this to offset the engine and reduces the space between the brackets.
http://i163.photobucket.com/albums/t...8/IMG_0779.jpg

Update:

Just picked up the left mount and just by looking on it I can see a couple of differences, so cross your fingers and wish me good look, now Its time to visit the garage...

There's a punched mark on the bracket, says MTD Co. I guess its a aftermarket bracket then? Dosn't matter as long it works.

Ok, so here's the result, the 383 rocket finaly got in place.

As you can see in the picture with the two brackets besides each other there's a big difference since the left bracket is a bit lower. The left bracket is to the right in the picture..

Anyway I hope this tread can help others from bumping into the same problem when switching to poly mounts... Check your bracket numbers first!!

Thanks for your interest, Im glad I didn't cut away the bushings metal tabs or modify the brackets and/or mounts.

good to hear its together! see, i told you not to start cutting, every time i get anxious and grab the sawzall, bad things happen.

Yeah man I know exactly what you mean with the sawzall. ( I promise 2 keep quiet about your missing neighbour. )
Anyway, the message is: There's always a reason why things do or do not work.

I was searching for posts on replacing my motor mounts and came accross this post. Now that I think about it, I cant remmeber if I put the brackets on the correct sides of the engine. Well Im going to replace out my poly mounts this weekend so I will be able to check then.

if you did, the exhaust would most likely be hitting the steering shaft

ok thanks. Thats not the case. I think I did mark mine before I swapped them over to the new engine.

Thanks for starting this thread, I'm dropping my engine in tomorrow and wasn't sure which side each bracket was for. Anyway this really helped me out, thanks fellas.

well, this is and old post and you got the problem fixed

but when i put in the energy motor mounts, i had the same problem. turned out that i had the mounts in upsidedown or rotated 180 degrees (don't really remember) and the tabs were in the way