Blow03SS

iTrader: (2)

I need to find out what I need to do to make my 408 as quite as a stock LQ9. My motor sounds like a damn train, and it sounds like its ready to fall apart at anytime. Im sick of it, what do I need to buy to make this thing quite again. MOney os no object at this point.

STRIPSTAR

iTrader: (4)

i havent seen that truck around. Looks nice. Um wouldnt some quiet catted exhaust and a mild cam solve your problem?

slow trap

iTrader: (22)

are you talking about your exhaust or engine noise ? if engine noise you may get some caddy lifters and get the proper preload and it will quitten down quite a bit if valvetrain noise is the culprit .

Blow03SS

iTrader: (2)

Im talking about engine noise. I was thinking about the caddy lifters but damn I just put in some new LS7 lifters. Im thining about adding a little more preload just to see if it helps and run some 7.425 instead of the 7.400. I don't think it will hurt anything seeing how big the window is on preload. I also don't think the Mahle short skirt pistons help with noise, but hey thats what I have to work with.

BTW I just had the truck on a mustang dyno. I only ran it up to 6300rpm and kept the timing at 26 degress. How much timing are you guys runnnig at WOT? Im also told you can run this thing up to 6900rpm. Anyway it made 472 like it was.

slow trap

iTrader: (22)

i'm running 28* in mine but some combos don't need as much as others.472 rw on a mustang dyno in that truck is very good numbers.

Blow03SS

iTrader: (2)

I agree, I was not unhappy with the numbers, but with the timing way down like that and the rpms being cute way short was a bummer. I will take it back down next month and add a few degrees to it and run it to 6900rpm. The graph showed that it was still pulling at 6300.

So what do you think about the longer pushrods and lifters?

Blow03SS

iTrader: (2)

Im starting to think that I should just run some comp rollor rockers so all this noise will be justified!

1999vetteroo

iTrader: (15)

Don't even think about putting in longer push rods. I tried running 7.425 and lost 20rwhp. Then tried 7.450 and lost another 20rwhp. Then went back to the 7.40 and my valve seals started to leaking oil. Learn from my mistake!!!