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BBC vs LS#/X Need Advice Please

Wish I had friends like yours, I have $ left over to buy them a beer.

Yeah I know these setups kill flywheel #'s, which is why I went for so high of flywheel #'s. 614 HP at the rear wheels would be insane! Then we would be talking about how much the tires were going to cost.
 
I cannot imagine it will dissapoint, unless it does not come with all the proper sensors, etc. I asked the rep and he said it was ready to drop into any vehicle, but things like


• Wire Harness
o Diagnostic Plug w/Check Engine Light
o Fan Relay
o Fuel Pump Relay and Wire
o A/C Control Wire
o Fuse Block for Circuit Protection
o Speedometer Hookup
o Tachometer Hookup
• Sensors Included
o MAF Meter-5 Pin
o 2 Oxygen Sensors
o Map Sensor
o Crank Sensor
o Cam Sensor
o Oil Pressure Sensor
o Knock Sensors
o Water Temperature Sensor


add up.

Does anybody know if my engine mounts will work for this setup? Are LS accessories interchangeable from LS1-LS7?
 
You'll need new engine mounts. I think it's "Dirty Dingo" that makes a good set that has fore and aft adjustability built into them.

Not sure on accessories, but there are a few guys on here that could tell you for sure. Hopefully they chime in.
 
cliles said:
Does anybody know if my engine mounts will work for this setup? Are LS accessories interchangeable from LS1-LS7?
Click to expand...

I used dirty dingo and as long as they all come from the same vehicle they will be fine but trucks and cars have different brackets and accessories.
 
We've been building a 408 for my buddy in my shop, should be impressive. Not 614 horse impressive. You'll love it. After assembling one I'm sold, good old small block chevy modernized.
 
cliles said:
Wish I had friends like yours, I have $ left over to buy them a beer.

Yeah I know these setups kill flywheel #'s, which is why I went for so high of flywheel #'s. 614 HP at the rear wheels would be insane! Then we would be talking about how much the tires were going to cost.
Click to expand...

You might be talking about speeding tickets though.:haha:Oh, and it should have no problem killing tires. With that engine you will want a well built trans, I would go with a th400 or 4l80. I would also consider a t case upgrade. That's a whole lot of engine and it will find the weak parts pretty quick if you use it.
 
Cruz89K5 said:
We've been building a 408 for my buddy in my shop, should be impressive. Not 614 horse impressive. You'll love it. After assembling one I'm sold, good old small block chevy modernized.
Click to expand...

408 as in a gen I 400 sbc or an ls engine? I have a 406 gen I that is similar to the Impersonator I engine built by chevy high performance, but with some upgrades. They got 525 tq. at 3500rpm and 420hp. Mine has a comp 270h cam, aluminum heads and 10:1 cr with a lot of head and intake work. It is a torque monster compared to my old 383. It puts my brand new GM crate 350 (in my 88 K5) to shame. The pickup (79C20) with the 406 is probably quite a bit heavier (6500lbs) and has a th400-gearvendor overdrive-14bff-33" tire-drive train to suck a bunch of power right off the top of whatever the dyno numbers may be from the engine. I have a fortune wrapped up into my 406. It is built for smog and is carbed.

That LS engine sounds like a pretty good deal-A boat load of power, and fuel injection that is ready to run. I was surprised at the cam size with that fuel injection. My 406 is 224/224 at 50 and has a nice sounding idle. I'll bet that LS has a bit of lope/unevenness to it. It would be music to my ears. I'll just keep driving around my modest mouse with 30+ year old technology:smirk:
 
Yeah it is supposed to be a bit lopey which I have grown to prefer. I'll try to get videos, dyno & mpg numbers sometime in the next couple of months
 
Finishing the Job Out

So I am trying to finish collecting all the parts I will need to complete the job and ran into a snag. I was going to swap in a 4L80E while I was at it, but have a hard time justifying it on a cost/benefit analysis.

There is nothing wrong with my tranny know, I just do not think it will last long behind the LS3, and thought there might be time/$ savings to replace them all together. However a built 4L80E is pricey, and comes with its own problems.

I know the 4L80E is much stronger than the stock 700R4, but I have read from vendors that the 700R4 can be built to be stronger than a stock 4L80E. If I go with the 4L80E I will have to (this is where the advice comes in) dick with the shifter, shorten the drive shaft, find a ECM for it, & get a 32 spline input gear.

Preliminary #'s
$2449 - 4L80E from MonsterTrans.com (no core return, however core charge is greater than what I can buy a used one for, so maybe some wiggle room there).
$150 - 32 spline input gear
$ 360 - SYE kit, cause why not if you are going in the Tcase
$90 - shorten drive shaft (this # is straight out of my ass)
some money for shifter adjustment, gasket, bolts that I may end up needing bringing me to somewhere around $3,100 to preemptively replace something. Meanwhile I could run my current 700R4 till it dies (may be longer than I think) and replace it with a 700R4 from monstertrans.com (I have heard good things in the past, speak up if they are junk) for $1435 (rated up to 650 hp), keep my lower first gear, not modify anything, and save $1,665 (enough for plasma cutter and pipe bender).

While my swap is "spendy" as some have coined it, I am not made of $ & as soon as the baby comes I'll be back to have limited funds for the k5. So you see my dilemma, I do not want to have to spend extra $ later or have broken down k5, but also do not want to fall into the mentality that I spent this much, might as well spend some more.

Any advice would be appreciated. This post has not been proof read.
 
Sounds like you have your mind made up and you are looking for our justification. I say keep the 700r4 till it blows, then swap in a built one or go to the 4L80E which can be run off the LS3 ECM. Or better yet get a 6L80E :deal:
 
I've heard good about the monster 700R-4, but have no firsthand experience with them. I guess it'll all come down to how you drive it. I do know the original ORD K5 ran a 700R-4 for years behind a healthy big block, including competing in TTC...

I'd say your LS is most similar to the LS7, not the LS3...
 
My mind is not completely made up, but i do get dissappointed when I read question threads like this, and the first post basically says "I know nothing, do all the work for me".

Thanks for the feedback.
 
I am abandoning this thread, and will continue posting at my build link in my signature.

Engine, Tranny, & Tcase are out. LS3 should be here tomorrow. 4L80E will be built in a week or two, NP241 will have its input gear and SYE installed by then to.

Thanks for all the advice. Now the real adventure begins, I am sure I will have plenty of questions if yall have the time.
 
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