Thread: GT Block conversion

So, I have read all I can read about how peeps have done the top swap on their GT's. On my end, I already have the GTP Supercharged, but am looking into converting to a GT motor with my top end. Reason being, well, my car has 216k on it, and I am gonna need new/rebuilt, or fairly used, so now is the time to decide.

Now, the GT peeps state to have the PCM tuned or leave it be, and allow it to adjust, if it can. My question is:

With me changing the motor, will I need to change the PCM to a GT? Will my GTP PCM auto adjust the timming, if need be, due to the difference in compression ratio?

The deciding factor is: Is it worth the work, for roughly only 5% more hp increase? If I decide to start to mod with smaller pulley, or better intercooler, will the higher compression ratio be a problem?

Sounds good. Headers aren't to hard to get, and it seems that is one of the first aftermarket parts everyone puts on anyways, so it will be easier to mount them with it out of car.

On the PCM, what's an average to expect for price to pay, when having this done? Will I need to have the car there, or just take the PCM to the peeps? Forgive my newbness on this, never had to retune a car. I usually deal with old school carberation. With the ability to just turn the distributor to adjust.

Originally Posted by bluegtp91

Headers can be had for about the price of a DP and PLOG...so why skimp? Especially on a high comp build it HAS to breathe.

I was once told theres "other" ways to mod a car so skipping headers was a good idea and just running PEM's or stockers and an I/C with the smallest pulley possible.

Its odd those with money for an I/C can't afford headers which play a vital role in the quest for power.

@98GTPCAL, about a week ago I was on ZZP's site looking at stuff, and came across some read, where they talked on how some company's don't rebuild the S/C very well, because of the pressed bearings and what not. They mentioned of certain things are needed in order to do the procedure, and that's what sets them apart from others. Don't get me wrong here. I am, by any way, saying Reptile can't do it, all I'm saying, is that it seems to be quite the job, without the right tools.

I find it hard to believe, that I couldn't do the headers while the motor was out of the car, since I'm just going to drop everything out from underneath? It be easier that way. I hate messin with lining up the spline on the tranny and only having limited space. I'll have to look over the engine compartment alittle, and see what are my choices.

ZZP says that about a lot of things... they ARE a buisness you know?

Spline on the tranny? This is an auto...

@minichopper: yeah, I forgot that you can just leave the torque converter atached tp the tranny. Been awhile since I have removed just a motor. I also deal more with RWD.

Anyways,I'm sure it is aleast alittle more work dropping all from underneath, than just pulling the motor, but not too much. I've looked it all over, and it isn't going to be like I will have to do the swap in one day, so I can drive my car the next. I'm going to take my time, and look at everything as it comes out. The car does have alot of miles on it, and I have no idea of what the condition is on all the other parts, except the fact that the tranny has been rebuilt recently. Got me some papers to prove that. Who knows when the struts have been done? It needs new front hubs, that has already been established. Sounds as though that the power steering pump is shot, or the rack and pinion is going bad, since I get a wine when I turn and it can be tough to turn from time to time. This is going to be quite the project, since the motor isn't the only thing I need to look at, so I am aproaching it that way, and deciding on what is easier all around for the job.

I do agree, the front header does look like an easy in and out, even with the motor in the car.