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Long time reader, first time poster, lol. I am building a LS3/LM7 2007 5.3 engine and looking to put a 6-71 roots style blower (old school) on this engine. Question is, would it be cheaper to piece meal the blower system or just buy as a kit? Another question is, I'm looking for a hir-rise manifold as well, that's why I thought about buying the blower in pieces and not a kit.
Anybody have a shop they like to recommend on buying most of this stuff?
Long time reader, first time poster, lol. I am building a LS3/LM7 2007 5.3 engine and looking to put a 6-71 roots style blower (old school) on this engine. Question is, would it be cheaper to piece meal the blower system or just buy as a kit? Another question is, I'm looking for a hir-rise manifold as well, that's why I thought about buying the blower in pieces and not a kit.
Anybody have a shop they like to recommend on buying most of this stuff?
ls3/lm7 and a 2007 5.3 are all 3 different things lol
ls3/lm7 and a 2007 5.3 are all 3 different things lol
go do some research
Thank you sir, I have done my research. It's a LM7 5.3 Vortec that came out of a 2007 Silverado. How are they all different? Everything I have read it is a LS3 (Gen3) in all sense and purposes. Unless I read this all wrong https://en.wikipedia.org/wiki/Genera...l-block_engine
If I am way off base then, please tell me what I have? I am all ears.
Thanks 01CamaroSSTx, I have seen those sites and although Speedmasters setup is exactly what I want, I am also looking for a hi-rise manifold. Most kits I have seen don't have one. I am not doing EFI so I don't need the rails.Besides, Speedmaster shorted me a crank stud nut and won't return any of my emails. LOL
Yes, it is a block I have cleaned up and bored and running stock heads which are the exact heads that were on it.
This will not be a drag car but just an old school show truck. I don't plan on doing more than 8 psi of boost, if that.
If it's an LM7 then it will have either 862 or 706 casting numbers on the cylinder heads which are small bore heads. The block can be bored to 3.905 and stroked to 383 cubes but 821's (LS3) or 823 (L92) cylinder heads which will work on a 4.00 inch or larger bore will not work on a 3.905 bore due to the larger intake valve so I would suggest staying with the cathedral style heads and maybe look for some 243 or 799 castings but if you're looking to lower the compression for additional boost then perhaps some 317's.
Yes, I have the 706 heads. So does that make it just a LM7 with interchangeable parts for the LS? Basically, don't call it an LS3 or anything like it? I suppose it will make a big difference when I have to look for parts for it. I plan on keeping the heads as is as they will work for my application.
That particular blower kit is for LS3 or L92 rectangular port cylinder heads. I'd contact them and see if they make a kit for the cathedral style heads I'm betting there is a kit for those as well.
Thank you sir, so do all the LS3 have rectangular port cylinder heads? Will the required balancer also fit my engine? - ATI Performance Products 917246
LS1, LS2, LS6, and some others all came with cathedral port heads but some engines came with a larger bore such as the LS2, LQ4 and the LQ9 which came with 4.00 inch bore. The LS3 came with a 4.065 inch bore and came with rectangular port heads which were 821 castings. The LS7 was the largest displacement LS engine that had a 4.125 in bore and used LS7 cylinder heads which haveba 12° valve angle where the other LS engines came with a 15° valve angle. Not sure but I'm sure the balancer will be fine.
Spend many many hours and learn about the various LS engines... but in general the 2005 and newer engines have stronger connecting rods and that is what I would be shopping for. The 2004 and older will work just above around 600rwhp they tend to bend the rods over time. 5.3/6.0/6.2 have a 3.622" stroke cast crank. LS3/L92 heads (rectangle port) fit on 6.0 and larger bore blocks (6.0 shrouds the valves more than a 6.2 or bigger would due to bore size and the huge 2.165" size intake valve. A 2005+ LQ4 or LQ9, L92, L76 is probably your best bang for the buck. Aluminum blocks run cooler than iron and will offer better knock resistance under boost.
Thanks gnx7, I am pretty much stuck with this engine. So far this has whats been done to it. I am after the cool (show) factor, no racing as it will go into a international scout lifted with 42" tires.
heads cleaned, new springs, decked and magged, new valve springs 120+ closed 295+ open
block cleaned and 3.785 bore
New forged pistons, piston rods, rings gapped to 0023, bottom 0025
new cammotion cam
2126LSR slow leak down race style lifters with axle oiling
Stock crank (cleaned)
Still looking to get push rods
If you have a different site to buy the blower kit I would rather do that. I am aware they are mostly in china, I can't get them to return any emails about their products.
Here's one from alkydigger - https://www.alkydigger.net/product/TBS2219.html - I'll need to contact them as it doesn't specify what manifold it is.
Thank you sir, I have done my research. It's a LM7 5.3 Vortec that came out of a 2007 Silverado. How are they all different? Everything I have read it is a LS3 (Gen3) in all sense and purposes. Unless I read this all wrong https://en.wikipedia.org/wiki/Genera...l-block_engine
If I am way off base then, please tell me what I have? I am all ears.
Thanks 01CamaroSSTx, I have seen those sites and although Speedmasters setup is exactly what I want, I am also looking for a hi-rise manifold. Most kits I have seen don't have one. I am not doing EFI so I don't need the rails.Besides, Speedmaster shorted me a crank stud nut and won't return any of my emails. LOL
Yes, it is a block I have cleaned up and bored and running stock heads which are the exact heads that were on it.
This will not be a drag car but just an old school show truck. I don't plan on doing more than 8 psi of boost, if that.
youre way off, ls3 is an aluminum 6.2, and lm7 5.3 wasnt made in 2007, if you have a 2007 5.3 its something other than lm7, most likely an ly5 or lh8
youre way off, ls3 is an aluminum 6.2, and lm7 5.3 wasnt made in 2007, if you have a 2007 5.3 its something other than lm7, most likely an ly5 or lh8
2007 was a cross over year on the trucks. You could still get the GMT800 Classic body style with an Iron LM7...If it came from GMT 900 in 2007 then it would be the Iron LY5. The LH8 was an aluminum block 5.3L and started in the 2008 production model vehicles.
I didn't buy one of their kits, but they helped me out a lot on parts. This is a 6.0 LQ4 with the LS6 heads. The lower manifold was an LS3 style manifold, so it has the square port -> cathedral port adapter on it. I sold it about a year ago and it's still out there, the next guy swapped out the mechanical fuel injection for a dual carb setup, but the blower setup is the same.
youre way off, ls3 is an aluminum 6.2, and lm7 5.3 wasnt made in 2007, if you have a 2007 5.3 its something other than lm7, most likely an ly5 or lh8
Just so everyone is on the same page, here is the casting number on the block:
The part number 12567392 refers to a GMC and Chevrolet 5.3L LS Gen III V8 OHV short block, specifically the LM7 engine. This iron-block engine was commonly used in GM trucks between 1999 and 2007. The LM7 is also sometimes referred to as the "Vortec 5300"
So it appears I did do my research, I accept your apology I took Gen III as an LS3, so my bad
I will more than likely buy the alkydigger Blower, been talking to them. So thanks Onbusy
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Blower LM7 build Questions 
I took Gen III as an LS3, so my bad