I have a silverado 2008 4.8 4door and I just bought the Texas speed and performance 220/220r with pushrods and beehive spring.and also have the 3200 circle d.
my question is how big can I go?can I go any bigger or that is the biggest I can go.im planing I’m the future to get some gears.but don’t know whichone to get.any suggestion?also is my daily driver and every once in a while I carry weight or will hit the track with street tires. (royal purple 1/4track)I really want to know what I can get for it.also thinking of getting possi unit.btw my truck is not flex fuel and does not for from 8 cyl to 4cyl.
any brand suggest for the posi unit.
what can I do to my heads to get the most out of them?
also what is a vvt and a dos delete kit?
im doing everything at the shop but I’m not sure what it is.
any help is wanted.

 

The bigger you go the worse your daily drive ability will be. A super choppy cam in a small 4.8 won't make it that nice to drive with or even tow with.

You are betting sticking with a cam like you picked then swapping gears to something like 4.10's to get a way better performing truck.

Lots of different options for rear posi units, read around a bit. A tru-trac is always a good option to use.

Keep in mind a non flex fuel truck runs smaller injectors, I forget exactly what size but they may or may not flow enough depending on what you end up doing.

VVT and DoD delete kits do just that, they remove those parts so you can install regular parts like what would come in the older GEN 3 engines or like your 4.8 has and the 6.0 that don't shut down 4 cylinders.

Stock cylinder heads are already super good flowing, some of the best out there in stock form.

 

on a 4.8 a 220R is a very healthy cam and like FFDP stated the bigger you go the worse it will be for daily driving, people have different tolerances as far as big cams and heavy trucks. i would recommend you keep that cam, and get some 4.11 gears to really wake it up. the 799 or 243 heads you have are the best of cathedrals. you could send them out to get ported and have them milled .030 to get that compression up in the 4.8, you may or may not need different pushrods if you do get them milled, just check with a pushrod length checker. i have a btr stage 2 truck cam in my 6.0 and is really fun to drive, it did leave me with the urge to go bigger, but with how fun it is on stock stall i cant complain. its a sleeper for sure.

 

4.10 gears for sure like mentioned above