Quote:
Originally Posted by Karch
Hi Bart,
<snip> Well, earlier this year, I broke down and bought a Trailblazer SS with the LS2/4L70e.
As such, and being such a research junky, I have learned quite a bit, and gathered some things that may help you.
My SUV is about 4800 lbs with driver, has 4.10 gears, and the LS2. These factors are rough on the transmission, as you would probably guess. My Trailblazer brothers, some of which are going pretty fast (low 10's), are beating up their transmissions fairly often.
As such, there are a few names that they all swear by in the transmission circles, and I would be happy to PM you the names or posts that discuss them.
I purchased HP Tuners software, as I hope to play with this more at a later date, but also got a mail order tune from one of the Trailblazer SS (TBSS) guru's, which I have been quite happy with.
Basically, the ecu uses 2 credits on HP Tuners.
Since I have the HP Tuners, and 6 credits left, I am thinking about grabbing one of the new GM LS conversion kits and implementing that onto my '65 455 instead of Megasquirt, but that's another story.
Another point I have realized and been told is the LS2/LS3's really wake up with cam changes, but the LS3 are really sensitive to nuances in the cam...off just a bit and it really loses on the low end.
Anyways, if I can be of assistance, feel free to ask. I don't have a lot of first hand knowledge, but I've been reading countless hours, and being an engineer, I take it from a practical standpoint...not intersted in peak numbers as much as efficiencies while still maintaining driveability.
Good luck.
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You can either PM me on your transmission contacts or post the links here, any help is much appreciated. I certainly want a strong transmission that will handle a good beating on occasion.
I want to be able to keep some sort of lockup converter, but I've heard they can fail from high-performance use, any comments?
There's a good chance I'll leave the stock LS3 cam in there. I want this engine to run well down low in the RPM range for good gas mileage, that's half the reason I'm doing this swap. Where I live the main roads are 50 MPH, 1600 RPMs at 50 MPH will be where I'm running a lot. I'm also considering warranty issues here, I doubt the warranty would stay in force if I tore into it to swap cams. Hopefully the oil pan swap won't be a warranty issue.
I'm pretty sure the best
average power will be had with the stock cam.
Anyone up for a dyno sim comparing average power numbers between the 204/211 .551/.521 lift LS3 cam and the 211/230 .560/.555 lift LS7 cam in this engine?
Quote:
Originally Posted by JC455
Hey Bart,
A couple of random thoughts...
1) You can get an upgraded LS3 w/ the GM HOT cam for just a little more money than the stock LS3.
2) Nevermind- you already got an oil pan.
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I saw the 480 HP LS3 with the GM hot cam, another 6 or 700 bucks for 50 HP is pretty good. I think I need that $600 to pay for my engine swap headers instead, they will add about 30 HP and make the exhaust hookup easy.
Quote:
Originally Posted by 455HOGT37
Good thread! I'm planning on doing the swap into my 68 ElCo, but I'm using the 5.3 and trans that is currently driving my Yukon around.
As to the LS3 vs LS7 heads, certainly the port shape is different. I just replaced the exhaust on my 08 LS3 Corvette with the commplete Z06 system. The "Z" manifolds are round port, while the LS3 is D port. Same spacing of course, so it bolts up fine.
As for fuel tanks, I have heard that the late Caprices (the rear drive, "bubble" style) have a in tank, plastic unit that is almost a direct bolt in to the old A bodies. Might want to check that one out.
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Mike,
The 5.3 is great little engine with great power and super fuel economy, I was impressed with the 327 cube/327 HP carbueted one tested in the Hot Rod crate engine comparo.
Already purchased a '64 direct replacement tank that's EFI-ready from SPI, but I'm sure that info will be valuable to someone here.
Bart