Leaderboard

Maybe this is just me being loony. Seems like a giant heap of work to wind up with just another V-6. Wouldn't it be simpler, easier, and a more-productive use of your time, money, effort, and enthusiasm to buy a car with the bigger engine already in it? Sell the one(s) you have to offset part of the purchase price. "I" would much rather fix worn-out brakes, suspension, steering, etc. on a replacement vehicle than to trade engines, wire harnesses, computers, cradles, etc.

Got around to doing the heater core last week. The cowl does not need to be touched period. Just remove the in/out hose clamps to heater core from under the hood. Once the heater core cover is off, the heater core has one screw that needs to be removed. That screw is attached to a bracket clamp that holds the two heater core pipes apart. New cores come with the clamp. The core itself is held tight by a metal retaining bracket that has two slots on top where the core slides in, and the bottom part of the bracket is a flat piece of steel that is springy. Once the top of the core is inserted into the bracket, pull down on the springy piece of steel to insert the bottom of the core. It's held in there good and tight. I used the OSC 98485 heater core. This was a one piece unit. No installing the individual heater pipes. It came with a new bracket clamp for the heater core in/out pipes, and it also came with a roll of foam padding that was peel and stick. The foam goes around the heater core. Just look at how it's installed on the old heater core.

You need the following parts from a 98-99 Monte Carlo z34/ lumina ltz wiring harnesses power steering lines exhaust downpipe (or have one made) heater core hoses if possible the alternator bracket/tensioner for the right angle heater hose connectors under alternator not 100% needed but nice to have. Other items Need to use the inner axle cups from the donor car and the outer shafts of the original cutlass Motor mounts bolt in no issues Donor car rad and hoses work Donor car auto trans cooler lines work Need a pcm tune to disable VATS. Once you have the parts, pcm and the wiring harness figured out it’s drop in You need to use the original subframe The best advice I can give you for the wiring, and OBD2, is to get a factory service manual from the 98/98 monte carlo/Lumina and for your year of Cutlass. You'll need to spend time ensuring each wire at the C100 connector matches from the monte carlo harness to the dash harness of the cutlass. I would say 75% of the wires will be the same, and you'll need to move or add 25% of the wires. You will also need to run 2 wires inside the cab for the OBD port, and I ran one into the cab for the tach as well. Not sure if that is 100% needed, but it works for me! There used to be plenty of information out there on this swap. I'm not sure if the old forums or posts have disappeared but this should get you going in the right direction. Once you get working, I'm sure you'll come across specific issues, post them here and I'll do my best to help as I can. Also check out this guys thread, for some troubles with this swap and how to overcome them (not my thread, but it'll help you see what you're in for).

Take some relief in knowing that if you had the LQ1 engine in there to get at the heater hose fittings one has to pull up the upper plenum assembly to allow one to get access to them.