98 Buick Century 3100-3400 Swap

[fatherof2]

Hello all. My name is Robert and I'm new to this site but I've been viewing here since about 2006. I have a 98 Buick Century with the 3100 motor in it. The car has around 178000 miles on it and while it runs well (needs a camshaft position sensor) I want to get some more power from the engine bay. I am an ASE mechanic and have built and swapped many engines over the years. I was one of the guys that had a 92 Dodge Colt with a fully built 2.0 liter DOHC turbo engine from an Eclipse in it that I built myself in my gravel driveway with nothing more than a floor jack and a couple of pieces of plywood.
Just a couple of questions for you guys, what I'm wondering is what exactly do I need to swap the small port 3100 heads and intake manifolds for a 2000+ 3400 top end? Is it cheaper and easier to just swap the 3100 for a 3400? I can port and polish heads and intake manifolds as well. What would be the performance gains on a 3100 with lightly ported and polished 3100 heads and an upper and lower intake manifold from a 2000+ 3400? I mean I can pick up a set of 2002 GA 3400 heads and a whole block for $75 with blown mains. At least that'll be the heads. I just haven't built one of these cars yet and I wanted some insight from some of the people here that have done these swaps or at least know someone who has. Is it cheaper to swap to a 2000+ 3400 or is it better to just swap the 3400 heads and IM onto the 3100 that I have?
I'd really really like to get as close to 200 to the crank as possible. What can I do with the current engine to produce this? I know they make 160 from the factory and while that is OK to some people, it's not to me. This will be an extreme budget build as I don't make a crap load of money and I have two kids and a mortgage...and so on so I need to do this on the cheap. Any help from you guys would be greatly appreciated.
P.S. I just sold my 95 Beretta with a 3100 in it and I was going to do this swap on it but the rear shock towers were rusting through the trunk and I got rid of it and got this Buick for $1200 off of a buddy. It's a 98 Century Limited with power everything and all leather interior...but no 3.8. That's honestly what I really want...a 3.8 swap. But that'll be more work and more time with my car down.

[Z26-T]

It's a straight forward swap. Main thing to look at would be the engine coolant temp sensor. Some systems use one 2 wire sensor and one single wire sensor (single wire for ipc), other system use a 3 wire. The 3 wire ect has the output for the ipc and ecm. I recommend researching that. To get 200 to the crank you'll need to have the car tuned for what has been upgraded. Yes, MAF will help adapt for the increase of air flow, but to get more power you'll need a tune.

Obviously you'll get more power out of a complete 3400 swap. But again, you'll need a tune to get the optimum power out of the 3400. Either way, make sure that you use the injectors that came with the car, not the engine.

Other than that.. just search around and see what other people have done. If you can do a engine/turbo swap in a colt in your driveway, i'd hope you could do a 3400 swap. But personally, i'd just do a head/intake swap if I was you. It's more cost effective. Buy that GA engine and get your head kit from rockauto.com

PS-less questions in one post makes it easier to respond :P