Not sure if 1.75 would be to large, I did a search and really didn't find anything.

Thanks.

 

Would be a stock setup with headers or do you plan on cam and building it up?

 

I plan on doing some mods, cam, stall, ported heads.

Thanks.

 

They should be fine I ran pacesetters in my h/c 5.3 and they worked great for that

 

i'd stick to 1 3/4. i'm running 1 7/8 on my LS1 at 11psi and that's only because i'm eventually swapping to a 416. i've seen H/C 6.0s run real good on 1 3/4 headers, so i'm sure your 4.8 will be good there. you want to keep exhaust velocity higher & if you ain't moving all the air in a given space, your power starts suffering - a 4.8 don't move as much as the bigger engines, so your low-end torque would start dwindling with exhaust that is too big.
the 1 3/4 catless system on my 5.3 is just right, so that's why it's also my recommendation to you. do a search for eBay headers on here - best bargain ever!