willyCJ

So I'm sure I'm asking a question which has been addressed numerous times before but I've tried searching every forum under the sun and haven't found a solid answer. Anyway, this place seems to be the best when it comes to gen III knowledge, so here goes and feel free to link me to other threads.

So far my habit has resulted in a jeep getting built and now I'm about to start a full on tube buggy. For this application, running a TH350 makes life easy (for doing a transfer case doubler anyway). However, I really like the idea of a modern powerplant since carbs don't do well going up vertical walls.

So here goes my question list
1) Do the bellhousings line up? I seem to recall reading that the LS1 has 7 bolts while the TH350 has 6?
2) What flexplate/torque convertor issues will I run into?
3) All I should need is a computer setup for a manual tranny to run the non-electronic Th350?
4) Does the LS1 share the same block (externally) with the vortec 5.3 (4.8 and 6.0 as well) engines? These seem to be cheaper, however the aftermarket for the LS1 kicks butt!

Sorry for dragging down the forum with stupid questions. Also, the for sale section of this forum is awesome, I love the activity!

Bill

LS1MCSS

iTrader: (18)

You will need a 98 LS1 flexplate, because it's dual pattern, or a TCI flexplate.
You need a spacer for the torque convertor hub, so it reaches the crankshaft, or a convertor made for an LS1. http://www.sdpc2000.com/search.asp?s...acer&doquery=1
The tranny will bolt up but with only 5 bolts out of six.
You need a VSS of some sort. http://www.magsensors.com/vss.html

'JustDreamin'

Hey Bill....

No such thing as stupid questions.....

The LS1 and the truck motors (4.8 / 5.3 / 6.0) are all the same externally (except the intake & front accessories). Most of the truck motors are iron blocks (a few are alum) vs the LS1's alum block. Weight-wise the difference is in the 80 to 100lb range (there is some dispute about the actual difference, I don't have a concrete number).

There are some differences among truck motors, depending upon year, basically the same as between an LS1 and an LS2. Cam position sensor moves, knock sensors are different, both to accomodate the displacement on demand feature. Also, some early versions of the truck motor are iron headed (like the '99 LQ4 6.0) and are significantly less desirable, make sure you know what you're getting.

There are also some variations of the truck motor to look out for. Like the flex-fuel stuff, which is capable of running on E85 (available for 5.3's) which use bigger injectors. And the Displacement On Demand (DOD) stuff, which is pretty neat.

And yes, the truck motors are a bunch less expensive. I picked up a complete 26xxx mile 2004 LQ4 6.0 for $1200. When shopping around, make sure you check around. Depending upon the area you're in, you might do real well to ship it from out of state. My engine came from Rhode Island, shipped to Baltimore for $130 (cost includes shipping an 80E trans too). My local salvage yards wanted $2500 and up for higher mileage older motors.

'JustDreamin'

mmmchickenboy

I believe there are some differences between car cranks and truck cranks in the height of the driveplate mounting flange.

protrax

iTrader: (4)

SWEET

BLWN1

iTrader: (6)

Good info.

'JustDreamin'

You are correct.

Early model truck motors (like the '99's) had a longer crank. Later model ones are the same as the cars, and therefore interchange. The longer crank was replaced by the car length crank and a spacer for certain transmissions (80E in particular).

'JustDreamin'

ls1jeeptj

I love all the Jeep activity in this forum! An LSX tube buggy would be fantastic - if you have any interest in a NP203 for a 203/205 doubler setup I think I have an extra one lying around..... tell me more about what type of buggy you are building!

I need to get some video up soon...

willyCJ

Well, so far I've done a CJ build up. Its running an AMC304, TF999, dana 300, a dana 60 rear end, dana 44 front and currently some 38 SXs. I stretched the frame 18" and the rear half of the old tub was rusted out so I comp cut the rear (tapered) to make room for the tire flex. The rear is still on leaf springs and the front is on air shoxs and a 3-link that I did. This is a picture right after the initial rollcage went in.


For the new 'buggy' thing I'm bouncing around lots of ideas. I picked up some 2.5 ton rockwell axles, both steer with 6.72 gears! I have 300' of tubing which I need to start bending at some point. I just found a TH350 bolted up to a NP203. I plan on doing a NP205 doubler case (roughly 4:1 low-low range). Here is a pick of the axles resting on some ag tires.


Anyway, I'm planning on a rear engine buggy, articulated steering at the yoke of the 205 which goes to the front axle. It should allow me to do a 110" WB and still have a turning radius After that, 4 link front and rear suspension, air shocks and the drivers seat should set right on top of the front axle for visibility reasons. I think that sums up most of the plans which have been formed so far.

I guess this is when it becomes obvious on my CJ that the engine was okay to begin with since I don't know enough about engines relative to everything else...

chevydad

is the spacer used the one that is needed to mate up to a th350? i have a 02 6.0 with the spacer under the flexplate. if i swap to a 98 ls1 flexplate, and use the spacer is that all that's needed?

62ls1

iTrader: (1)

From what I have been told - if you buy the $200 TCI flexplate for mating a TH350/400 trans to an LS1 motor, you do not have to get the spacer or have a special converter made. The flexplate takes care of that and you can use any TH350/400 converter that you want.

If I am mistaken in this guys, please correct me because I am planning on getting the TCI plate. Thanks

88s10

iTrader: (8)

If you are running a 350 or 400 with no vss witch timing map will the pcm use park neutral/ in gear? Is it mandatory to use a vss for the pcm to know your in gear?
thanks

LS1MCSS

iTrader: (18)

I may be mistaken, but I think you would still have to have the spacer for the torque convertor hub to reach the end of the crank. Most people use the TCI flexplate because it has two convertor bolt patterns. If I am wrong, someone correct me, so I don't buy something I don't need because I am in the process of switching from a T56 to a 200-4R in my car.

Eskimo

iTrader: (9)

I'm doing something similar to my rock buggy.. '04 5.3 to 700R4, 4.7:1 t-case. Also have 2.5 ton Rockwells (both steering), but mine are the top-loaders. It's going into my '73 Toyota FJ40, which is already tube from the dashboard back.. 4-link F&R, full hydro steer, 42's. Needs to be done by July.

http://www.rnrfab.com/rich/fj/da_cruzah.htm

It outta be fun as hell...

Back on topic, I've been *told" that with nothing more than the spacer & longer bolts, along with a little egging out of the holes, I can bolt my 700R4 TC right up.

chevydad

i'm pretty sure your correct

62ls1

iTrader: (1)

OK, I spoke with TCI. If the TCI flexplate is used, you will not need to buy the spacer. If you use a gade 8 washer and a longer converter bolt, as necessary, you can make sure the hub is not hitting the flexplate / crank and you're all good. If you decide to use a LS1 flexplate, there are more issues (like the bolt pattern) and you will need to use the spacer and washers.

So, for the sake of ease (and because I need a flexplate anyway) I am going with the TCI flexplate and will use washers as suggested by TCI to space that snout out.

12secSS

iTrader: (30)

It will use the Idle Spark Advance when under a certain TPS setting. Anything above that TPS threshold and the Main Spark Table will be used, if you do not use a MAF it will only use the Low Octane table. Your tuner should be able to correct these issues.

justin b

iTrader: (3)

i got a conversion kit on mine and it works great

FORDRECOVERYEXPERT

iTrader: (5)

I Used A Stock Truck Tranny (th350) Out Of A 79. Bought The 4000 Stall From Jegs, Used Stock 99 Flexplate, And Custom Xmember. Quicksilver Did The Shifting, And A B&m Supercooler Up Front. Use Either A Stock M6 Ecm, Or You Can Use The A4 Entire Car Harness, U Put The Neutral Safety Switch In Neutral, And The Comp Thinks You Are Reving In Neutral. No Vss Needed. This Setup W Stock Lid Exhaust Only 99 Camaro Went 7.7's In The 1/8th Mile. It Didnt Even Thro Any Codes!!

jdime20

ok, just to make sure, my 99 ls1 with the 99 ls1 flexplate will mate right up to the th350 i have?