obs to ls conversion going different route

[89sierra]

hey guys i am starting out with an 89 z71 stepside sierra that i have done a frame off resto on. i have not figured out if i am going with the 5.3 or the 6.0l it depends on what i can get the better deal on. now some may question my next decision. i am planning to go with a carb set up and run my 700r4 with tranfer case. i figure it is easier to run the carb set up then mess with the computer and wiring harnesses and fueling. i can use all my brand new fuel pump and braided lines with just a fuel pressure regulator with by pass. the reason i plan on using the 700 is 1 because i have it. 2 i dont not have to change any mounting locations and can use my stock drive shafts and 3 because i have a friend who builds trannies and is going to put the 5 planetary gears in it and build my 700 up to handle the power and it also does not need any electronics to run it. my main questions are with mounting the motor to the transmission. i know that the tranny will bolt up to the motor minus 1 bolt. i know you need a spacer for the flexplate. where i get lost is can i use the stock ls flex plate with my convertor and drill new holes? do i need a whole new flex plate? do i need to run spacers inbetween the flex plate and my converter also does the spacer go inbetween the crank and flex plate moving the flex plate farther from the engine causing the starter to not be lined up? or does it goe between the flex plate and transmission?

[pl4yboy]

Honestly, in my opinion, it sounds like you're scared of the electrical portion of this swap. You're going to spend more money on the carb setup than you would the entire wiring portion of the swap. You can easily use your 700r4 without any major wiring, so that shouldn't be a problem. I think in the long run, you'd be much happier biting the bullet and going fuel injected. You'll get better mileage, drivability, and tuning than you can ever imagine with a carb. I wouldn't dream of an LS with a carb unless it was a race or offroad only application. I'd still probably go fuel injected then.

[Botlfed]

A wise man once said. Carbs are for salads and lawnmowers

[bstill]

To me, a carb on an ls is like a super hot girl hooking up with Napoleon Dynamite. It just ain't right.

Just get Nelson to build your harness and tune the pcm. Then all you have to do is plug and play.

[Tig]

Noone had answered his questions in regards to the tranny, hah. I wish I could help you out, I'm just not sure.

If you want to go carb, thats cool. To each their own. I wouldnt say its not right, its what he wants.
If not like said, Nelson has what you need I think Mast has everything to.

[RedHeartbeat]

I just don't like the 700r4 cable driven detent setup.

[RPM Graphics]

you still need an ECU & tune, even if you run a carb. to me it's double the effort. you still have to tune the ECU & now manually tune your carb.
if you use the right motor mount adapters the trans will line up on the factory cross member & you can still use the factory drive shaft.
the way you're talking about going is going to be twice as much work.

[89sierra]

ok as much as you guys want to hate on carbs that is what i am going to be running. i already have a 750cfm carb. the kit for the ls to carb swap is 668 on summimt this is intake and electrical box and chips for coils just need my carb on top. so to me it seems like a no brainer. i have the engine out of a 2004ss that i got for 500 with no wirinng or computer. so for me to find the computer have wiring built then have to mess with pumps and filters and having everything shipped accross the boarder i will be well over the 700$ for the intake setup. on top of that all you guys with the ls are fuel injected i want my truck to be different i am building it to the standards i want. thats why i am doing it not someone else. plus with the carb all i need to tune is a screwdriver not a laptop or have to send the computer out everytime i need something changed. so i guess no one can answer the question of what exactly is needed for the 700 to work behind ls. redheartbeat i know the tv sucks but i am trying to work with what i got and i may just put a manual valve body in there to get rid of it. this truck is by no means a daily driver or will see more then 5000km a year and lets face it i am not here for mileage. if i was i would be buying a yaris not dropping a 6.0l in there running 37 and 4.88s.

[Botlfed]

any v8 harness elec tb harness will work man, or switch to a cable driven tb to keep your pedal, you dont need an SS one. not being an ass here, but im curious as to why your even going with an LS motor, i mean if youre gonna run a carb anyways why not just sell that LQ9 for a good chunk, then go get a sbc or a bbc, and not hassle with any of this other crap, just wondering why your going through all this just to run a carb'd ls. No matter what youre doing you questions can be answered here in time, lots of knowledgeable guys here.....im not one of em.

[89sierra]

ya i understand about the harness and any computer working. its just that to have anything tuned and stuff i need someone else to do it and to ship it out which costs big money from canada. and there are a couple reasons i want to go with the ls. one because they are a better design. two they have more hp to start with. three easier to get hp out of reliably. i would need to put a good chunk of change into a small block or big block to get it to where a stock ls would be. and my final reasons are i have a friend who dropped a bone stock tb ss motor in his regular cab short box and is running 4.10 gears wtih a built 4l60e tranny running 13.3 in quarter mile. my friend has the same motor out of an 05ss though dropped same carb set up i am on it and dynoed at 410 hp was put it into the same style truck with 4.10s and his truck is running 12.3. with the exact same set up on truck just carb not efi.