It's Decision Time

[JohnnyReb]

Building a motor a little at a time and then swapping in the end don't make much sense. Especially if you are on a budget. Don't get in a hurry, a hell of alot of projects like this end up never finished. If you have the 3400 already put it on a stand in the garage and do it right the first time. If the 3100 is still running good run it while you are building a engine. If you build as time and money allow you have a better chance of ending up with what you actually want. You will actually save money by building once instead of in stages, that money saved can be spent on more goodies for the 3400. Just the money you will save on gaskets and small stuff would just about pay for a boneyard tranny and rebuild kit for it. While you are at it grab another sub from the boneyard, they almost sell em for scrap price. Ahh new engine, rebuilt tranny bolted to a sub. Pull it in the garage Sat night and drive it out Sun morning finished. Also do you have another car to drive. If this is your only way of gettin to work, or the parts store it would suck to be in the middle of a top end swap and find yourself walking because of some unforseen problem.

[IsaacHayes]

Yes I agree. Having only one car sucks and is the reason why my car isn't that crazy (but it is modified). Takes a lot of planing and preparation to get it all to work smoothly without using another car. Especially on mine when I did the intake swap, I had to re-clearance the lower again when I finally bolted it down and saw where the rockers would hit.

[JohnnyReb]

The good thing about these engines is that they are pretty cheap. Drive around for a hour and you are likely to find a donor car sittin, probably with a bad LIM. The OP was contimplating a top end swap and then later swappin in the 3400 as time and $ allow. For the cost of 2 gasket sets a subframe and boneyard tranny could be had, I think he already has the 3400. Provided he has the place to store and work on it I would think the results would be alot better if he rebuilt the motor and tranny then assemble it on the sub when he could. I can remember years ago working on my only car at night in the driveway just praying I could get it running for work the next day. Thankfully now I have a heated 3 car, two story garage plus a larger garage a couple miles away. I'm pretty new to the 60v6 world but not to the swap world, have plenty of experience with Chevy and Ford FI swaps and its not a hard task to build, wire and run a FI engine and have it ready to install. With everything planned and tested you can pull a car in the garage and swap overnight.

[Sidewinder]

Well, I've been giving it some thought recently, and I think I know what I'm going to do. I'm going to pick up a full 3400 if I can find one, if not I'll just get a shortblock (I found an engine locally that looks promising, so hopefully that will work out). If and when I find it, if it is a full 3400, I'm probably going to swap over the top end onto the 3100 and leave the block for me to to work on.

After this, I'm going to clean up the block and make sure it is driving ready, at which point I'm going to get a 3500 top end to put on it. All of this will be properly clean, ported and upgraded, and painted or whatever else I decide to do to it. I'm going to make sure I have everything I need for the swap before I do it (pcm, possibly a tranny, etc). While its out I'm going to uber clean the engine bay and possibly paint it. Then the engine will go in.

I'm going to book off an entire weekend or a bit more to work on it. I'll be doing this over the summer at some point (maybe not this summer but next). This will hopefully give me enough time to work on it, and I'm not worried about having it off the road, because I will have my choice between the HHR, Impala or Suburban to use if I need it while it's being worked on.

If I do swap in a new tranny, I may look into doing a 5spd or 6spd manual, haven't decided on that one yet, I may just stick with the auto. Do you guys think the 4T60e can handle a 3500 top swapped 3400?

[IsaacHayes]

Honestly save your self the $$ in gaskets and don't put the 3400 top end on the 3100 if you are going to build up the 3400 and swap it in. Yeah you'll have to wait longer for power but put that $$ towards the 3400 build.

If the 4t60e is healthy yeah. PCGUY and 3400 Modified have 3400/3500's with cam and headers.

[Sidewinder]

Ok, well getting the whole engine isn't going to happen (the wrong price was posted for the one I was looking at). So I'm going to look for a 3400 shortblock to start working on, and hopefully find it for cheap.

I know Milzy sells shortblocks with spun bearings for really cheap, is this a good way to go or a bad idea?

[1988GTU]

Buy a complete engine.

[Sidewinder]

The problem with that is I can't seem to find a decent 3400 complete for under $650, and for $100 more I may as well buy a 3500.

I do, however, have a complete 3.4 DOHC I'm still debating on using since I have the donor car (and its also a Monte Carlo). I'm hoping to get it running in the spring then I'm going to take the car for a test drive and see if I like the DOHC. This would save me buying the new engine entirely and I can just go straight to cleaning it up and modifying it. I just don't like the gas mileage it gets.

[Sidewinder]

Out of curiosity, how much do you guys think a 3400 swap or a 3500 swap will be (minus the cost of the engine) altogether? I've been reading around and the swap cost I've seen seem hardly worth the slight power gains.

[silvergtjrad]

Out of curiosity, how much do you guys think a 3400 swap or a 3500 swap will be (minus the cost of the engine) altogether? I've been reading around and the swap cost I've seen seem hardly worth the slight power gains.

For just the swap, its not worth the gains. You will have a lot more potential for the future though.

[RedBird]

um.... your car has a small port 3100 right? Moving up to a 3400 will cost you only a bit more than the cost of the engine itself, since it's damn near exactly the same, and you'll gain anywhewre from 20-30 hp. that's a pretty decent jump for the amount of work it'll be(not much). if you were to rebuild the 3400, with ported heads and intakes, and a healthy cam, you're power is going to jump even more(if you can tune it). keep looking around for a 3400 if you think $650 is too much. i got mine for $300 with 90k and a broken oil pan. put a new pan on it, dropped it in, and ran a can of seafoam through it, and it's spotless on the inside now, and extremely healthy

[19Cutlass94]

I got my 3400 with 8000miles for $675 and that was shipped to my door. You can find good deals out there you just need to look.

[Sidewinder]

Well its just that the 3100 I have was rebuilt about 2 or 3 years ago and is running great, and I was planning on getting the large port 3400 top end for it anyway (which is cheaper than the engine). I don't see how spending and extra $200 - $400 is worth getting 5 extra horse and 10 extra torque. I mean I guess if everything eventually got ported on it. I guess my biggest concern is getting an engine thats worse than the one I have now.

[19Cutlass94]

Building motors is money. Your not gonna spend $100 and get 30whp. It just wont happen. You wanna play you gotta pay. And it just happens that engines are not cheap. With my motor, buying it and all the parts and powdercoating Ive got close to 2k in it.


get a 3400 on the cheap side, tear it down and learn about the motors while rebuilding

[Sidewinder]

I know that I need to spend money to get horsepower, I just don't really see the extra cost of getting a 3400 for the small amount of gain I will see. I was planning on getting a large port 3400 top swap for my 3100 anyway, and the extra money could be used for porting and rebuilding the heads and intakes.

I wouldn't mind getting a new engine, but in my area I can't seem to find a decent engine below $650 (and the 650 is with 100k+, after that the mileage is worse). I can get an engine cheap from farther away but I have no means at the moment to pick it up and getting it shipped will probably be expensive.