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LQ9 in '87 Monte Carlo SS- ideal trans/computer combination?

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Old 01-04-2019, 05:41 PM
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Default LQ9 in '87 Monte Carlo SS- ideal trans/computer combination?

Ok, I've got an '87 MCSS, that I want to turn into a mild performance/daily driver. I want to make it mainly a highway cruiser, that I can take on long road-trips, while still having 25+ MPG on the highway... Looking at the results of aftermarket tuners (with only cold-air induction and free-flowing exhaust), I've seen ~330-340 RWHP, which is perfectly acceptable for me. And the aftermarket cams push the HP up, at the expense of bottom-end torque, which I have no intentions of sacrificing. There will be NO hot-rodding the engine, just get the most of what I can out of the "stock" package...

So I picked up an '05 LQ4 engine, that I'm boring .065" over, and using used LS3 (2010 Camaro) pistons. I'll be running the LQ4 cam, rebuilt 317 heads, yellow beehive springs and replacement lifters. I'll do moly rings and clevite bearings. Basically, I'm turning this into an overbored LQ9. I have a truck intake manifold (DBW throttle body) which I won't be using, and have no harness, computer or anything else.

I'd considered upgrading the stock 200R4 trans, but it doesn't make sense if I can get a 4L60E/4L80E trans, with torque convertor lockup capabilities. Bottom line is, I'm looking for the proper combination (in terms of trans, computer and harness) to have programmed to my engine, so that I can attain the stated goals. 4L60E or 4L80E out of what? With what computer? I'm going to use the LS6 intake manifold, shorty or mid-length headers, 2.5" dual exhaust.

What should I look for, to put together a simple package that can be easily programmed? (I'll modify the harness myself, as I easily have the skills.)

Of course, my budget is "no price is too low," as a wife and 3 kids make spendy solutions unrealistic.

TIA for your input...
Old 01-04-2019, 06:58 PM
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https://www.summitracing.com/search/Part-Type/Torque-Converter-Lock-up-Kits/Transmission-Type/200-4R/
Old 01-11-2019, 09:21 PM
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I just did an lq9 in my 87 monte.
A lot of what you are asking depends on your budget.
25 mpg I doubt will happen, stock 3.73 gears won’t help that, an 80e definitely won’t help that.
The 200 has a better over drive ratio and a 200 is a good Transmission for a daily and you can keep the lock up feature.
You can keep your transmission in the stock location, stock driveshaft, stock crossmember and shifter also.
Old 01-12-2019, 10:25 AM
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Easiest swap is the trans, wiring and pcm that matches your 05 motor (trying to mix and match parts around the time they changed from 24x to 58x can become a problem). That being said you can build the 200-4R and use an adapter to mate it and another to connect the tv cable and then just program the pcm as a manual trans so it isn't looking for a signal. Either option works and they've both been done before so it's really just personal preference.

https://www.cartechbooks.com/techtips/ls-swaps-transmission-and-clutch-guide/
Old 01-12-2019, 11:39 AM
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I would do a mildly built 4l60e if you want good fuel economy, run it with a stock pcm and dbc .
Old 01-14-2019, 09:21 AM
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I got lucky, picked up an intake with full harness, computer and DBC throttle-body from an '03 GMC Savana 2500, for $100. I'll have it programmed, and leave the pigtail for the 4L80e trans, but run the 200R4 for now.

Thanks!
Old 01-15-2019, 10:41 PM
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That's the way to go
Old 01-17-2019, 12:07 AM
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This one was a toss-up between Conversions and Auto Trans, but it certainly doesn't belong in External Engine. This forum is taking some abuse this week!




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