Doing a 3500 swap instead

[johnnymossville]

^^^^ Very good Issac. I have thought about picking up a 3500 also as I can get a couple of them with low miles for $400 each. Interesting note though is I was looking at3400s and I can't get a lower mileage one for less than $800 around here. LOL

[IsaacHayes]

Good choice. You'll have stock compression and quench, and .1l more displacement. Throw in a cam and headers like PCGUY and you'll easily be at 240 and beyond. I'd keep the UIM, but if you absolutly have to change it, you could put a 2000+ 3100 UIM on there just to fool everyone.. Hey it's just a 3.1L!!

Yes for the crank trigger.

Yes to swap the 3100 fuel setup, but you'll need bigger injectors even with a stock 3500.

FPR, some have gotten away without grinding, some with some grinding and a little adjustment and bolting the fuel rail down moved out of the way like I did (with a tiny bit of bending of the metal fuel line). Or you can use the WOT bracket that moves it out of the way some extra. Not a big issue.

Vacuum lines are easy to figure out. If you go with a LX5 TB, then you have 2 vacuum ports right there and a fresh air port you can run to the rear valve cover breather tube and not have to drill a hole for that in a CAI pipe.. You'll need one vacuum line to the FPR (mine goes to the LX5 TB) and one to the transmission/vacuum ball feed. That one I have going to the the 3500 UIM where the evap purge solenoid was, tapped with a 1/4" NPT and put on a barbed fitting there. I'm using the 3500 MAP sensor cause it fits right on the manifold.

Powersteering is non issue.. You may need to swap your 3100 timing cover over, but you probably don't need to. At most you'll have to cut a stud off the 3500 timing cover to route the 3100 accessories the same way I think.

Tuning, is your car a 96? if so I think it will be the same as PCGUY's then. 97 has more memory and more tables to tune. DHP is the way to go for that. HPtuner I think supports 97 monte carlo PCM...

O2 sensor, re-use yours if it's fairly new. Depends on what exhaust manifolds you use. If you can fit the 3500 ones then you'd probably just use one bank or the other, or plug them and put one O2 where they merge (unless you go duals). 3500 O2 I'm not sure if they are different. I think SuperDave had issues using them, but maybe it was something else in the end? I think it's a different plug on the sensor though so just keep yours or get a new one for your 3100 so you know it's good. I'd go denso or ac delco, not bosch.

3500 spark plugs are fine, same thing as the newer 3100/3400's use. It's an iriduim tip plug. You could even use the plain ac delco's just fine. Just keep to an AC Delco plug that was used in any 3100/3400/3500 and you will be in specs.

Mounts, non-issue, other than the trans to engine bracket, I think it's the one by the differential. That has to have the holes elongated see PCGUYs thread. Also the AC compressor bottom bolt won't bolt up, but non-issue, or you can oval out the AC bracket and AC compressor so that you have enough "play" to line up the bottom bolt like Barry did with his 3500 swap.

PCGUY's thread covers it all basically. As long as you are 96 you should be fine on tuning. 95 or 94 would mean OBD2 or OBD1 swap to tune...

Do it right and save up for a cam and headers... Or at least cam first off cause that's near impossible to put in later once the motor is in the car.. headers can be added once it's in the car of course...

[Sidewinder]

Well I've run into major problems with the hybrid that has prevented me from continuing with that build; problem being that I can only find complete engines and not separate parts for it. Kinda detrimental no?

Anyway I gave it some thought, considered upgrading the 3100, doing a built 3400, or even just swapping an L67 in and calling it a day. However just recently a junkyard nearby posted up some complete 3500s for about $350 that I just cannot pass up (I'm 60 bucks away from getting one). So I've settled on a complete 3500 swap instead of the hybrid to get me to my 240 crank hp goal.

I've read through a good chunk of PCGUY's swap thread and I have a list of things I need to consider in order to complete this swap. I was wondering if you guys could point anything out that I have missed. I am debating on either working with the 3500 UIM or getting a 3400 UIM.

I am planning on doing some work on the engine. I haven't decided whether I am going to cam it, but for sure I'm going to do porting on everything and get the TCE 65mm throttle body. I'm also either going for the S&S Headers or I'm getting a set of shorty's and doing a true dual exhaust.

Anyway, here is what I have:

Crank Trigger: I need the external one sold at the store correct?

Fuel Rail and Injectors: I can use the 3100 fuel rail I already have correct? If I do any performance mods either I also need bigger injectors. Will the DOHC ones work for the mods above because I have a set on my parts car.

FPR: Just the clearance issue which requires grinding or there is a bracket too correct?

Vacuum Lines: I recall a couple people mentioning vacuum lines but I not sure if there is an issue can someone clarify?

Power Steering: 3100 stuff bolts up the same correct?

Tuning: I can tune this with a '97 Lumina PCM and HPTuner correct? If so I just need to get the tuner.

02 Sensor: I know they are in different spots so they just need remounting, but where is a good place to get new ones from?

Plugs: Can I use stock 3500 spark plugs or should I get something else?

Engine Mounts: Judging by the pictures of malibu engine bays the mounts are different. Can I take the mounts off my 3100 and mate them up to the 3500?

All the 3100 accessories will work right? Is there anything else I am missing/need to consider.