X-Body swap guide posted by Richard Durost on MTS board
- X body swap guide by Steve Tuggle, posted by Posted by Richard Durost
on 9/3/2002, 2:55 pm on MTS message board.
Steve Tuggle did this guide based on his experience.
For those who have been contemplating installing a Cad into an X body
(Nova, Omega, Ventura II, Apollo, or Skylark (75-79), here's what it
took to get one into my 75 Omega.
First, I looked for an Eldo because of the motor mounts and rear sump
pan. Only other things I would need were a RWD driver's exhaust
manifold and RWD starter. I found a 73, then pulled and rebuilt the
motor. Then I yanked the 250-6 out of the Olds. I bought a TCI BOP to
Chev bellhousing adapter and frame motor
mount kit from MTS.
The engine mount kit won't work as shipped because the Eldo motor
mount studs sit about 1-2 inches forward of the crossmember. So, I
used 3/8" steel plate, 5 x 9 in. I located the three stock
crossmember bolt holes (there are more holes than that, in typical GM
fashion) on the plates using spray paint with the motor temporarily
bolted to the trans, and the original Eldo motor mounts bolted to the
engine. Flat stock works fine because the crossmember and motor mount
resting surface are at approximately the same angle.
The front drain plug has enough clearance to loosen and remove (about
1"), but the rear sump and plug extend below the crossmember. The
second day I had it running, I mashed the plug about 1/2" into the
pan going across a bridge...instant clearance! I
installed the manifolds, and upon lowering the motor in, I found I
had to unbolt and move the steering shaft outboard an inch or two,
then adjust the linkage clamping bolt down below. The column shift
linkage even clears the manifold (had to bend the upper rod arm
w/bushing back a bit)! On the passenger side, I had to grind the
inboard lip on the upper control arm forward bushing to clear the
#1 exhaust port by about 1/16". There is plenty of hood clearance
with the stock intake, but an Edelbrock will have you cutting the
hood and looking for a scoop.
Fortunately, the stock oil pump and filter easily clear the front
sway bar. I used the Eldo flexplate and converter on the Chev TH350.
I had to grind the TH350 inspection cover to clear the snout on the
RWD Cad starter.
I removed and plugged the pipe thread heater hose fitting on the back
side of the passenger head, and drilled and tapped the flat boss on
the passenger side next to the thermostat housing.
For cooling, the Eldo radiator was way too big, so I got a v8 Nova
radiator and shroud. Same width as 6 cyl., but three instead of two
row. Works fine up here in Washington with mild summers, but for
anywhere else, I'd recommend the heavy duty version, which is 6"
wider or a four row if you can find one. Fan lines up perfectly in
the Chev shroud, looks like it was meant for it. Mix and match
radiator hoses. Used all Cad brackets and accessories. No welding or
major custom fabrication needed.
Well, that about sums it up, not too bad in retrospect. Next on the
agenda is a posi, then intake, then headers, then......