American racing stainless 1 7/8, no cats. I know this probably isn't a popular opinion but I'm actually concerned that I'm going to end up wanting some quieter mufflers once I get rid of the cats. My true duals are already obnoxious with cats, for daily driving or long highway trips. It probably wouldn't be quite as loud in-cab if I hadn't insisted on side exit in front of the rear tire.

 

Ah that is why they are expensive lol

That is a common opinion. I would go ahead and put your order in for mufflers now.

 

I kind of figured on the 5.3L crank, trying to avoid machine work. The main guy I went to for machine work isn't taking anymore new work, and has his business for sale. I'm leary of trying a "new" shop. I most likely would have been OK with the parts store crank if it had been .010" on both the rod and mains.

 

I run 2 dynomax bullets and a big case Magnaflow on my truck to kill some of the noise. Granted... I have an LQ4 with 862 heads, 10.4:1 SCR and small valves. When I swap to my LQ9 with larger-valved heads - I hope it's still liveable.

 

@86 IROC

 

LSA blower ordered. Talked to local Machinist, he's been building race motors for years and has some fancy 5 axis CNC machine and a bunch of programs he's written himself for it. He has a program where he can open up LS3 heads to lower compression ratio, he also said he can look at the pistons and can probably machine more dish into them. I assumed you'd do that on a Lathe but I keep forgetting how much tech has trickled down over the years I'm pretty sure he meant fly-cutting or something like that with his snazzy machine.

Anyway I didn't know if either of those practices are common or if one is preferred. They both sound like walking a fine line, I assume you don't want to make a head much thinner on boosted application, and I also assume aftermarket Wiseco pistons probably use about as little material as reliably possible.

 

I love how every local machinist builds race engines.

Also I would just buy the proper pistons for the application. Not really sure why you would go that route. Head thickness is preferable (giggity)

 

You are right, that is what I should have done. The sales rep at Mast told me it would add months to the order to get Wiseco to custom make some pistons so I thought I could just run higher compression but lower boost. Robbie Draughon, the machinist here, brought up the idea of reducing the pistons or increasing the combustion chambers, that's why I'm asking about it here, to see if it was unheard of.

I'm sure just about everyone who wrenches does some degree of "building race motors". Robbie actually stopped doing stock rebuilds a couple years ago and now his machine shop only does high performance stuff. I hadn't realized that until today.
Back on the topic of compression ratios and boost levels, I ordered a 2.95 and a 2.55 griptec pulley for the blower so I have the options. I was thinking about getting 2 different tunes done so I can just swap and go if I so desire. I don't know how the stock pulleys go on but Rosh the sales guy at Boost District made it sound like the hub that they're sending me makes it easier to change, I think it's 10x allen fasteners or torx maybe. I'm interested to see how much documentation and specs/info comes with the LSA.

 

Control the power you make with your foot. Don't monkey around with pulleys.

AS IS what will your compression ratio land? Stock LS3 are 10.7:1 and people toss LSA blowers on them regularly... And that's with stock ring gap

 

Your pistons are 4.020? MAST only lists 4.070 and 4.005 for the rotating assembly options.

I talked with Hank today, same as you and he said anything other than those 2 options are custom order. Price jumps $700 for custom pistons to $2650 plus the longer wait time is likely.

He also said 10:1 compression is pretty much no problem, they had engines doing well up to 20 psi (not necessarily this rotating assembly, though there customers were reporting good things about this one and boost).