Also while we are all here, should I swap heads to my 317s I still have or continue to run the 862s with the turbo? I think I'm at 10.4 compression with my 862s on stock LQ4, **** I hope so that's what I put down when the dude tuned it. I remember reading and working it out it late one night and writing it down never to think about it again but I digress, I have the 317s just sitting in my garage I would just need to swap them out before I put the turbo on, sadly that will increase cost as I will need new gaskets etc.

 

By the way these are stock 862s, I didn't think about adding 2" valves until after I had them done and really didn't want to take them back

 

I would leave the 862s. Makes for better response. You could add a 2” valve and do some chamber work to unshroud the valves if you wanted to but stock 862s have made 800+hp tons of times

 

The only thing I don’t really want to do is run meth. I think I should be okay but I’m not 100%. I may be fine doing it but it would not be my favorite thing right now

 

I made a 3" downpipe off my on3 78/75 till just under the truck and used an adapter to make it 4" and ran the Mbrp diesel exhaust out the back. Cam is a texas speed low lift 5.3 boost cam 218/224 .550/.550. Works great in my 6.0 and sounds good! I have a fti 10" 3200 80e converter and with this setup the spool is pretty much instant.

 

Would it be worth it in terms of gains to go from a 3” DP to a 4”?

Sounds like a good setup!

 

All depends on how much power you want to make, don't need 4" for 5-600hp but I like the way it sounds better and helps with spool. Plus the cheapy diesel exhausts fit good under my 00 ext cab 1500 and they're all 4" or 5".

 

Yeah I think what I am going to do is just do the 3" back and have a 4" electric cutout just for ***** and gigs

 

Just run a 3” cutout, there are a lot more options and they are more reliable. You will still have two 3” pipes for the exhaust to escape.

 

Fair enough, probably save me some coin for other things. I think I have the turbo priced out all I need is to get a fuel pump. Am I going to need to new fuel rails/line or will the stockers work? Still looking for maybe upper 500 lower 600hp