12's on spray in the Silverado, yes, but barely.
Hooker makes longtube equal-length headers for these trucks with a BBC conversion. They don't have EGR, AIR injection, or O2 bungs so you'll have to add the O2 bungs at minimum. The reason I am mentioning this is because all BBC heads are under-valved. That means that the valves are too small for the bore - that's just the way it is. Long tube headers do wonders on these engine for improving exhaust flow. Seriously - it's amazing. Those hooker headers are huge - 3.5" collectors, 2" primaries, and they are such a pain in the *** to install that you'll be using words from such bowels of your vocabulary they could raise the dead. (There are brakeline and steering shaft clearance issues on the driver side and on the passenger side the rear upper control arm bushing needs to be heat shielded or it will melt.) The improvement is worth 50-60HP and that's no exaggeration. Since the same percentage in gain off the nitrous oxide can also be realized on it that would get you into low 12's.
You can spray the hell out of a big block. The bottom end is very stout and they don't have ring land problems the Gen-III/IV SBC engines have. Even still, 11's is a lot to ask of a long wheelbase truck.

 

sorry bout that james but its a short bed and i put the stepside bed on it kuz it weighs practically nothing that and ive never seen a four door stepside and well i like stepside better lol

 

Some tips on the swap itself:
Get the following from salvage truck/junkyard/new:
- 19" radiator, upper brackets, and fan shroud
- cruise and throttle control cables
- upper and lower radiator hoses
- transmission cooler lines
- transmission cooler and support bracket
- hydrobooster, lines, and cooler
- fuel line assembly (it will connect to existing lines on the frame)
- transmission crossmember
- oil cooler lines
- Air conditioning compressor lineset for L29
- harness/fusebox/pcm

This really is a simple swap. The motor mounts on the L29 will drop right onto the existing isolators on the frame. If you decide to use the stock exhaust manifolds keep in mind the passenger side one will interfere with the rear upper A-arm mount on 2WD trucks. This is why the 454SS truck had specific exhaust manifold with a constrictive relief cast into them. You can get some clearance by chopping off the top 3/8" of the inboard side of the A-arm bracket and use stock L29 manifolds. Coat the exhaust manifolds in Cold Galvanizing Compound for a nice protective grey appearance if you don't want them to look like rusty crap.

The only reason I was thinking 4-door is because you said it was in the original post.

 

lol it is a 4 door but shortbed and thanks alot but do i still gott change the crossmember it came with the 4l80e stock

 

Okay... so it's a 2500 truck already.
Come to think of it, I guess there were no GMT400 four-door 1500 pickups.

Your swap will be even easier.
Steal the dually's exhaust.

 

This one made some ***, stock heads, unopened longblock, boost profiled cam, headers and a tune.....D1SC @ 16psi, 83lb injectors, methanol and a good sized intercooler. Beat it sencelessly for 48,000 miles before I sold it..

1997 C3500 Dually Crew Longbox with a 5-Speed. Ill dig up the dyno sheets and post them.

Id skip the overdose of spray.....That old addage...If your gonna spray your gonna pay goes far....

Just my opinion.

 

Yea but I made it from an eight lug to a five lug so no do my goals sound possible with brodix heads and some long tubes and I do got the exhaust from the dualy james and cool butminesfaster looking forward to see the dyno stats

 

I chee wow, your post makes my head hurt. Not sure what this guy is currently doing but they are decent motors compared to the tbi 454's.

 

Hahaa I think I'm finished here

 

lol thanks guys anymore guys got some info lemme know i appreciate all the info and thanx in advanced for future posts