not sure why you guys have issues with the stock pump...i ran a stock pump on a heads/cam/ported fast 408ci with a largeish cam and had plenty of pump...maxxed my 36lb injectors though.

 

i have thought my numbers were low as well. im going to do a compression test on it to see if i have low cylinder pressures.
im also already looking into doing a 408 kit

 

Stew, I've seen some make the stock pump last. Most however do not last and end up failing around 350ish hp.
Dlt(david) had his stock pump on his H/C lq4 and he never had a problem with it. I guess its just a luck of the draw kind of thing

Im not hating on your setup man. You have alot of good parts and as long as you like driving it that's all that matters. Just saying, for the amount of time/money/parts in that truck it should make more power. IMO

 

i know it should. trust me. its a quick truck too. im going to test cylinder pressures when it stop raining. if i do have low pressure im just gonna run the biggest shot of juice i can until i put speed holes in the block

 

Unless the original owner of my silverado replaced it; I'm still running the stock fuel pump. The truck has 160k miles on it.

I guess I missed where you said what injector size you upgraded to. Graph is weird. I've also never seen a spike so far in the trend line like that.

I wouldn't try to blow it up. You could save some money selling off the shortblock. If it doesn't have any internal issues. If you're going 408, find you a bare block and start from that. I think your power issue is in the fueling and tune.