My friends old ford mustang was not centered in the frame.. I don't know about level..

It was stock too.. Always bothered me.

 

I know quite a few Mopars that weren't centered. I would suppose centered is best, but if it isn't there doesn't seem to be any negative effects. If steering or engine accessories, starter etc demand you put the engine off center then do it.

 

It is not that important.........Say, if a steering box was in the way and moving it over an inch would solve it, it shouldn't matter.

As for level, most builders want it to slope back a few degrees....why, I don't know.

 

If you have a choice center it. Regarding level, production engines are almost never level, 4 degrees or so , down toward the rear. This usually has to do with getting proper angle in the driveline/rear pinion.

 

my ramblers are offset to the rt about 2" from the factory....
as far as the carb sitting level, when was the last time you drove on a level street?
it's NOT that big of an issue in real life BUT it does LOOK better...

 

I always try to level the heads, side to side and front to back and let the carb fall where it will.
But you do what you have to do sometimes.

 

".....I always try to level the heads, side to side and front to back and let the carb fall where it will......."

Same here. YOu do have some leaway though. Probably one of the most extreme factory tilts I have come across are the 63/64 full size Ford with an FE. The engine tilts back pretty good and it's really noticable when they had the long oval air cleaners on the Tri-Power and Dual Quad intakes.

They actually the rear carb pads taller than the front pads (and a slight angle if I remember right) to level the aircleaner and gove the allusion of a leval engine.

The picture below is my 64 with an FE and Thunderbird Tri-Power intake. On the T Birds the intakes were level so when you put one on an engine in a 64 Full size the engine angle is really noticable.

 

Vertical:
the engine angle should be the SAME as the diff angle. so if the diff is pointing up 4 degrees then the engine should be pointing down 4 degrees. the engine and transmission don't need to line up but the "centerline angle" needs to be the same AND the drive-shaft angle should be less than 4 degrees. in fact, the engine/trans centerline should not line up perfectly with the diff in order to load the u-joints properly.

the same goes for the horizontal. the offset (left or right) doesn't matter as long as the engine is straight with the frame (same angle as the diff) and the drive-shaft angle is less than 4 degrees. most offsets are to the right (passenger side).

you remember your trig formulas, right? tangent x=(rise/run)

Long drive-shaft and slow rpms (low numeric gears) will make the engine alignment less critical.

you can find the above information on the web.

 

I agree so far.

I set mine so that the engine/driveline angle is between 2 and 4 degrees and equal. I don't worry about the carb pad being level, in fact I like it to slope forward a bit. Under heavy acceleration the fuel sloshes to the back of the bowl and that is part of the reason why the carb flange is tilted forward.

Provided I have the right angles, here is how I set up mine. I put the engine as low as possible for CG and hood clearance reasons, but I make sure the oil pan has proper ground clearance. Then (because I almost always build lowered street cars) I tuck the tranny up as tight as I can in the tunnel... as long as that doesn't put the driveshaft angle more than 4 degrees. In 90% of what I build, I'm using factory frames and tunnels so that's never a problem. I only ever have about 1 degree to work with.

I would say that most frames/chassis setups would allow anything from a level crankshaft to 2 or 3 degrees down at the tranny should be great. You can test fit and fine tune things if you find your driveshaft angle is greater than 4 degrees deflected or less than 2 degrees deflected. In cases like that I try to engineer adjustable trailing arms or (if its a leaf spring car) I'll use perch wedges or custom spring shackles to alter the pinion angle.

It sounds difficult, but once you get it all mocked up, measured, and visualized it should be pretty straight forward.