Blk61,what year was the aluminum 283?Did it use the 461 casting aluminum heads that were to be used on the 60 FI corvette?The MM exhaust system was a work of art in an era of exotic factory exhaust systems,the only ones that were comparable visually were the chrysler max wedge and 64 track hemi.Did the MM use dripper valve covers,and did it literally use the Z-11 crank or was it a larger main journal like the later Mk.IV?Also do you know the CFM rating of the holley they used?Was it the first of the big 800-850's?I know ford was having them make 780's by then and chrysler used a 800-850 on the 64 track hemi.Just trying to make the MM not so mysterious to me.
Here goes....the 283
HEADS cast 6-24-59
Casting number 3772895
BLOCK, cast 3-4-59
MYSTERY MOTOR
Dripper valve covers-Yes
However to accommodate keeping the droppers and use the more efficient roller rockers we made a set of spacers to raise up the covers.
HEADERS
I totally agree!!
Bill Howell the engineer assigned to the MM told me they got 75 HP more out of the engine by just using these designed headers.
They still had to design them around the car, steering shaft clearance, oil filter, frame etc.
Note the less than desirable bends in the lower pipes. These are NOS pipes also!!
CRANKSHAFT
Yes, it is the exact same crank as the Z-11, same casting number as my Z-11. The lower end of the block is exactly the same as the 409/Z-11. The pan interchanges.
HOLLEY CARB
I have forgotten!!
Wrench's article might have it. I'll look it up if not found.
I actually have 3 carbs, 2 complete and one for parts.
Actually, the first time Chevrolet used the dreaded (ford) carburetor on any engine.
Jody will love this!!
If anyone stumbles across any Mystery Motor parts let me know.
They really are only useful in two ways, one to put on an engine, two, as a wall hanger!!
Pat