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Inputs for some "GO" with my "SHOW"

5K views 27 replies 10 participants last post by  soontobesrt 
#1 ·
Well now that I have the SRT8 clone look for the exterior of my '05 Laredo completed, it's time to give it some giddy up. However I can't make up my mind of which route I want to go. Here is what I'm thinking about:

- Get the 4.7 forged and toss a turbo on
********* Wondering if the weak 235hp is a horrible starting point
- Swap to a 5.7L and still turbo
********* Wondering if it's worth the cost
- Swap to 5.7L and stroke to 6.4L
********* Wondering if I will just drive from gas station to gas station

Looking for pro's and con's to my options. Thanks in advance guys!!!!
 
#6 ·
I was doing this same things for ages man. Ended up like 60% of way there, bought the entire rear SRT8 axel, the transfer case and front carrier assembly, already have the NAG, just need a TCM module and then some tuning. Only thing holding me back was the 6.1 Hemi and all modules for it etc. The cheapest they can go for shipped are like $6-$7k which is the hardest part. Stuck at this point until $ becomes available or a cheap 6.1

Im about $3k deep in total driveline stuff but motor is the real $ and then labor. I plan on doing all mechanical stuff myself with a buddy and maybe my pops but all stuff will need reprogramming (dealer) and probably some dyno tuning etc.

End of day its a solid $10k swap if you can do labor, if not add another few grand on top for all that.

If you make a solid living Id look into it, but then again trade your Laredo for a used SRT8, they go for high 20s with decent miles!
 
#8 ·
Just looking around and doing some research and have a few questions....

If I decide to go w/ the 6.4L stroker...

Am I limited to only Hemi engine's from Grand Cherokee models or can I use any engine as long as I pick up the correct PCM?

Can I buy a 5.7L bare block or short block to help keep costs down?

Will I be able to keep the stock transfer case and 545RFE from my 4.7 Laredo?
 
#9 ·
The 4.7 and 5.7 use the same trans don't they???
 
#11 ·
I thought the 3.7 and SRT did?
 
#12 ·
yes the smallest motor and largest motor in the grand uses the same trans, the NAG.

the 4.7s and 5.7s use the RFE.

Dont take this as gospel, I know in the early WK years it was but they seemed to change up options in the later WKI years
 
#13 ·
I know the 4.7 and 5.7s use the same transmissions. After doing more research it seems sharadon is the way to go if I plan on producing any significant amount of horsepower.

So back to the hemi stuff. Going to try to find the most screaming deal possible. Should I hold out for a grand Cherokee engine and hope I can score the harness and all that good stuff to go with it? I found that if I go brand new with a stroker kit it will run me about 3k.
 
#20 ·
or.......

* 9" rear diff
* RWD converion (simply take out the front diff and axles and plug the outer axle spline holes at the wheel bearings)
* Big fark off engine..... could be a Mopar, or even a Chev (!)
* Suitable tough as nails tranny and custom tailshaft
* Retain original PCM to run the Jeep but add aftermarket engine management.

Mix it all, and enjoy :)
 
#28 · (Edited)
^ LOL, yeah SRT and 3.7 use the NAG which is proven trans and rated at around 450ftlb of input torque (im not doing conversion lol) hence the 580NM in Wa580 :)

I wouldn't worry about your trans if you had the NAG, but seems you have the RFE which Id tend to say isnt as proven or beasty as the NAG in the SRT (thats why it got it) it would just need some serious TCM tuning to allow if to change shift paramemters to accommodate for increase hp and all new motor parameters (tricky stuff, you'd need to call Dave at B&G or Andy at PWR or Bill at Paramount or even Eddy at SHR, someone like that whos in the trans game and know these platforms oh so well.) So try and grab that w/ the 6.1 if you can

As far as a motor, if you get anything beyond the 5.7/6.1 with all factory electronics you are going to struggle making all the modules and oem features of your truck work as well as risking many other electrical issues down the road.

That said what Marlin said is easiest way to go. Grab an aftermarket stand alone ECU and have someone familiar with Hemis (one of guys above maybe or even Westbury Jeep up in NY could help) set it up.

Main issues will simply be getting everything to mesh and work and then be reliable. If you go OEM you KNOW it will work as designed but dont forget youd need:

6.1 crate with ALL electrical wiring for motor (PCM/wiring)
Trans (will come w/ motor from most places fi you go used) (TCM module/wiring)
ESM/TCM/PCM reprogramming from dealer I believe once its all hooked up
Im not eve sure as the exact swap hasnt been done but when you try and swap another VIN part into diff ending letter VIN I dont think the modules like to recognize each other and canbus freaks out. Not exactly positive, but Im sure its a PITA getting electronics from the 6.1 part to work with 4.7 electronics, hence the huge headache!

Then as far as other stuff goes, to retain functional AWD, you'll need:
NV146 (SRT t-case) or aftermarket equivalent (Bill has something)
Front/Rear diffs (SRT8 has the Dana 44 3.73s) Not sure how long the factory open diffs in the 4.7 or the oem half-shafts will handle the 6.1 torque??? would suck to find out

So all in total this could be had for around $10k (+- 3k or so) Id say pending what kind of deals you find/get

Then you'll need all the labor/tuning which will add a wee bit, maybe another $3-$4k realistically so say $15k+ at best to get her up and running.

For that, Id sell/trade your whip and finance the diff for an SRT8 or something similar :) Then you have the real deal
 
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