Hey guys, I have been helping my neighbor install his 427 with a 5 speed tremec tonite and having problems with installing the driver's side exhaust manifold. I am thinking that his frame stands are wrong or he has the wrong manifold. The manifold numbers are 3994045. I have been reading old post about frame stands, are the frame stands for big block two different heights causing the motor to be slightly rolled up on driver's side. The best I remember the frame stands were the same height, I do know that they measure 2 5/16" wide. Any help would be greatly appreciated.

that # say it for 1973-75 left hand 454 off the police package

Yes for 67-68, not sure about 69, the BBC frame stands are two different heights. The crossmemeer is offet as well to clear the steering box. He needs the right motor mounts for the subframe... Also, put headers on it... Unless he is doing a numbers car... The engine will appreciate it the easier breathing and he will get better power...

Does the 3994045 have a large area carved out of the casting for steering box clearance? The correct Camaro manifolds, like the 879 casting, have a big divot in the casting, and it still fits pretty tight.

http://img.photobucket.com/albums/v239/ekammerer/111_1116-1.jpg

Keith, tell him to buy freaking headers !!!that 427 is gonna sound like a dump truck with manifolds on it!!

You need the correct frame mounts and rubber motor mounts too. Engine will move to passenger side by 1 inch. Engine is not tipped, passenger side is shorter and driver side is longer. BBC trans mount is drilled with 1 inch offset to passenger side. Also the exhaust manifolds are great. Most cars have headers, and i changed to manifolds after 20 yrs of driving. I don't understand the truck sound? Also the engine compartment is quiet now and the temperture under the hood (WOW)is down. My friends can't believe i don't have headers buy the way it sounds. Thats the conversation now when i open the hood.

It does have the divoted area on the manifolds for the but not sure to the degree that Eric posted in his pic, I will check on that today. The crossmember was came with the package from Keisler, so not sure of the offset there. I thought the actual motor mounts not frame stands didn't really matter, that they were just regular big block mounts, I know his are polymounts from Energy Suspension. As far as headers go, its his car and I think he wants the manifolds.

It does have the divoted area on the manifolds for the but not sure to the degree that Eric posted in his pic, I will check on that today. The crossmember was came with the package from Keisler, so not sure of the offset there. I thought the actual motor mounts not frame stands didn't really matter, that they were just regular big block mounts, I know his are polymounts from Energy Suspension. As far as headers go, its his car and I think he wants the manifolds.

http://i900.photobucket.com/albums/ac203/bk69/carpics891.jpg

The Energy Suspension Engine mounts are great ! Yes, the drivers side frame stand is about 1" taller then the passenger side. You are right, the engine IS rolled over towards the passenger side. The offset can be measured at the air cleaner stud as 1". Yes, it is tilted. The transmission crossmember is offset to the passenger side by .500" and .750" forward. This is all from the small blocks location, which is from center. Many aftermarket transmission company's do not do this with their crossmembers, and they are wrong ! This is most likely where your problem is.

Easiest way is to look at engine from front of car. Carb stud will not line up with hood center,might have to look at cowl center if front end is off, will be left. If you are using 4 speed check for correct bell crank to.
Look at "all" componets with respect to the 1 inch off set of engine. Correct fan shroud will need off set too. The engine is not tilted. It is moved over to the right at it's 3 points of contact. The engine is level in the car.

Mine is installed on correct 69 BBC Camaro frame stands, with the 350/396 engine mounts, and is not tilted at all. Offset is to passenger side, but engine is perfectly level, confirmed during install.

Charlie and Eric, With the driver's side frame stand taller than the passenger side, how can the engine NOT be tilted ?

1. Driver's side is 2.5 inches from base to the top of the bracket. It measures 1.75 inches from base to center of the bracket bolt hole. It is GM part # 3950113. NLA

2. The passenger side bracket measures 2.0 inches from the base to the top of the bracket. It measures 1&3/8 inches from the base to the center of the bracket bolt hole.This is GM part # 3950114. NLA

I said above that the difference in Height was 1", my mistake, it is only .500" (1/2").

You can install the engine on small block frame stands, and the engine will be close to level, however your exhaust manifold and most headers will not fit. Lemon's makes headers that will fit, with the engine on center.

My small block is not even perfectly centered as the 302/350 frame stands are not exactly the same height. (neither are the 307/327's)

The engine can not sit unlevel in car per fuel leveling. I think GM shortened the passenger mount and lengthed driverside geometrically with the V of the sub frame and the crossmember. The driver side frame mount is not the only difference. If unlevel in car this would also put a bind on the trans mount. Also affecting the z bar angle to. To me thats why the engine is basically slid sidways for all the other angles to work. I think alot of people believe that the engine is just rotated, but it would not work correctly. Driveline angle would be involved also. Going with Eric, all my componets are original with the car.

Charlie,

Go get me proof to what you say. The transmission IS moved over 1/2" so it is not in a bind.

If you don't believe me, ask David Pozzi (on this site) he will tell you. or PDQ67 (Paul) who is not aallowed on this site anymore, but I think he can be found at nastyz28.com .

Also from CRG :

In order to gain engine compartment clearance, big block (BB) engines were offset 1 inch to the right (towards the passenger side) by means of asymmetric brackets. 1967-68 BB frame mount brackets are 2-1/2 inches wide (but not the same as SB) and use the same engine mounts as 67-68 302ci and 350ci. For 69, BB frame mount brackets were redesigned to use the new thicker, narrower, engine mount also used by 302ci and 350ci. BBC bracket pairs are easily spotted because the left bracket is noticeably taller than the right in order to achieve the engine offset.

to clarify things, a big block chevy,a mark iv engine will not sit uneven in the engine bay!!

TJ
i don't know were you are going?:confused: My engine is level and toward passenger side.

Charlie, We are talking about 1/2" over the distance of about 20 ". Your carburetor float is only about 3". Your carburetor may only be talking about 3/32" difference on your float ! Park your car on level ground and measure from your exhaust at the engine ports to the ground, see what you get.

I will have to look and see if I can find pics from the correct angle without the engine installed, but although the driver side is "taller" relative to the mounting surface, I recall it being angled and the through bolt hole being positioned such that the through bolt holes on each side are at the same elevation, or nearly so. It's about the geometry, not the realtive heights of the stands. Regardless, mine sits level side to side.

After Thinking about this some more... The frame mounts are mounted at a 45° angle, so the height difference is actually only 1/2 of the 1/2". This would be 1/4" in height ! 1/4" over approx. 20". So your carburetor float would be about 3/64" or about .047 from level.

Thanks Eric i could not figure out how to explain it like you did. The angle of the frame mount on the sub frame vs the hole position in it make it level.

Keith, tell him to buy freaking headers !!!that 427 is gonna sound like a dump truck with manifolds on it!!
I told him!!!!!!!:D

Also the crossmember is not FLAT. If you move the mounts to one side so they are no longer centered, one is going to be mounted physically higher than the other so the other must be made taller in order to keep the engine level.

I'm virtually certain that the engine is moved horizontally to the pass side, and the mount height is designed to compensate. Tilting the engine would necessitate that the transmission crossmember mounting surface be angled,(which it isn't) and would cause the Zbar to be un-level (not good geometry.) Also, the shifter handle position would be rotated to the passenger side creating potential interference issues with a console. To compensate, the mounting bracket would have to angle it back, (which it doesn't)

Eric is right, it's geometry 101

After Thinking about this some more... The frame mounts are mounted at a 45° angle, so the height difference is actually only 1/2 of the 1/2". This would be 1/4" in height ! 1/4" over approx. 20". So your carburetor float would be about 3/64" or about .047 from level. On the 67/68 mounts (shown in picture) the difference is only 3/16".

http://i263.photobucket.com/albums/ii152/tjs69_photos/engine%20and%20frame%20mounts/6768BBCFRMT.jpg

http://i263.photobucket.com/albums/ii152/tjs69_photos/engine%20and%20frame%20mounts/enginecomp.jpg

http://i263.photobucket.com/albums/ii152/tjs69_photos/engine%20and%20frame%20mounts/driverside.jpg

http://i263.photobucket.com/albums/ii152/tjs69_photos/engine%20and%20frame%20mounts/passengerside.jpg

double post

Keith, tell him to buy freaking headers !!!that 427 is gonna sound like a dump truck with manifolds on it!!
Even with Flowmasters?

i think based on my experienced you can still drive your car though your exhaust manifold (http://www.familycar.com/autoparts/exhaust_manifold.html) might be faulty. just dont rush it to the highway for some race. but you should still wait for the part to arrive to be assure. goodluck.


===princecasanova====

Keith, I put a 427 in my car years ago using the SB frame stands because I didn't know any better back then. To get the exhaust manifold to clear the steering box, I have to pull the long bolt out of the engine mount and jack the engine up to get the manifold in place, and then hold it while mom lowered the jack. I'm not sure what the casting number was on the manifold, but it was all but touching the steering box when I got it back together. I drove it for years that way with no problem. I would change the stands out and get the correct engine mounts if he is so inclined, but he'll need the BB bellcrank for the clutch as well. He'll also need the BB 4 speed crossmember if you switch to the right frame stands, but they are reproducing them now, so it's not too hard to get one. If he's planning on hooking the heater up in his car, the heater core and cover will need changed as well, 'cause the is no way you'll be able to get the hoses on the heater core nipples with the engine offset. Basically, it's allot of work, and a small fortune to get the engine in there like GM did. Guess it depends on what your friend wants to do. It can be stuffed in there with the SB hardware, but it's going to be tight.

I love it when this happens and it's not me.