geterdun
+1y
Vortec 4.3 great choice. I put one in a 90 ext. auto, from a 92 pickup. It is a drop in fit. Use the original radiator, if metal.
Original shifter can be modified with two bends to use on the GM automatic transmission.
78 Chevy motor mounts saddled in a set of "u" brackets lay right on the original mount pads These mount has the anti jump clip for when a mount breaks and less give when throttle is nailed.
I used a conventional flex fan which I reshaped for opposite wind flow (serpentine belt).
Bottom radiator hose I made from a standard hose cut in two pieces, with a pipe going under the engine to the outer side (radiator intake on driver's side). With all the GM engine mismatches, NAPA probably has a one piece for an eighty-something vehicle. My 77 Bandit was 6.6 TA, but they put in 403 Olds too.
Leave the distributor out to set into body (firewall).
I ran a HEI distributor (86 pickup) and fabricated a Chevy two barrel of your choice adapter to bolt to the original intake Or these are available online. If you plan on a cam and four barrel, do that instead now, before the install and have the distributor tuned to the cam and carb of choice.
You will have to modify the routing of the emergency brake cable I think drive shaft clearance.
Power steering, right there by the sector on mine. A/C is on correct side.
Seems I had to cut off the end of the driver's side exhaust manifold and turn it a quarter or third of a turn (the stud ear) to clear the frame and braze it together.
Make changes to the transmission tailshaft housing for a cable speedometer instead of electronic, just parts change, but easier on the bench.