Well my last post didnt stir up much info so I thought I would try a new title.
So here goes ~
Say I have 2 98s one 24v auto (truck A ) and one 98 12v auto (truck B) and I want to make truck A a 12v and B a 24v what items other than the engines need to be swapped? PCM im sure, how about the computer for the trans (is there one) anything in the dash such as gauges different? Please let me know the items that arent interchangable between the two.
Thanks

 

ummm no idea...but it sounds like a very expensive project....12 v vs 24 valve has a different cam, different pump, different comp and on and on why do u wanna turn a 12 valve into a 24 valve?

lots of guys on here will trade their 24 valve for ur 12 valve im sure....so think about it

 

Well I guess im just not explaining my self enough here?
I just want to swap entire engines between the trucks. The auto trans will both stay in their original trucks. What im trying to find out is what other "non" engine parts also need changing such as the PCM?

 

You will have to change PCMs but no big deal since you will have both.
Don't know anyone who has done this swap but from my recollection of both engines don't think you will need anything extra at all.
I think what you are doing is an excellent idea, I personally wouldn't own a 24 valve.

 

Thanks Bill
I was hoping to hear your take as I know your up on allot of this stuff.
Do you think there would be any differences in the fuse boxes? As you said I will have all the parts for the swap I just was hoping for some heads-up on other parts that also need to be changed prior to starting.

 

I know DTT makes different valve bodies for the 12's vs. the 24's... Though, there may be fittings that differ between the 2, I know '98 was a bastard year... (Some lines were push on, some thread-in, etc.) You may or may not want to change the trannies as well.

The gauge cluster has a slightly different redline...

Since the 12v has no engine computer, obviously you'll need all the wiring from that to stay with the 24v.

 

I guess to be on the safe side, completely gut both trucks and swap everything from one onto the other..........that way you won't have to worry about not having the right parts. They are already there, you just have to do all the work to remove and re-install!! Good luck


~Nick

 

Thanks for the replies guys and keep the info comming. The more I think about it the more I seem to think its the way for me to go.

 

Why not just p-pump the 24V??? You have the DTT and twins already...just need the p-pump.

 

Mainly the cost, a P pump conversion still pretty pricey. If I figured this one right and I can buy the truck Im looking at right then I should be able to do the swap and sell the doner truck for the same as I paid for it. So other than say 100hrs of my time I will have a 12v in my truck. The doner im leening towards already has had "a little pump work" according to the owner so we shall see.

 

dash wiring is different, speedo cluster is different. computer plug and under hood wiring is different also something to do with the fuel lines and the tank pickup or sending unit in tank is different betwen pre june of 98 and post july of 98

intercooler is different also the cruise control i think is different too. my o2 cruise is drive by wire i believe and my 98 12v is cable.


good luck.

 

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WOW Dash wiring too? I figured on all the wiring harnessses from and including the PCM to the to the fuse box. The insterment cluster I figured on but wasnt sure other than the tach. Wonder what would be different with the fuel pick-up? I have a FASS on my truck now so I wonder if I can use it and just bump up the pressure with a spring change? Good work guys its giving me more to look at and think about.

 

This probably true comparing an '02 to a '98 but not '98 to '98.5.
The '98 was designed for the 24 valve engine but it wasn't ready on time so a 12 valve engine was used.

 

Why not just swap your performance stuff over to this 12V and sell yours with its stock stuff?

Is it a nice truck?

 

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Yeah theres not much on the used market to compare. Its got 104kms about 60k miles and clean as the day it was new, plus many, many add-ons thru out the truck.

Well after talking at great lenghts with Harry and Piers at PDR I think its probably not a worthwhile endever. If the doner truck I found had less miles I may have gone for it but..... So it looks like for now I will just bite the bullet and Oring/stud the head on this engine. I guess on the plus side I will be able to step-up to 60-65psi of boost (when I can afford new sticks ) For you guys information I ran 11 months with 50-55psi pretty much daily befor the stock gasket started to puke. Not to bad from a engine only designed for 20psi in my book. Thanks again for all your responses.