Can I run my stock 1995 Z28 injectors with a 383 kit ?
I have to decide tomorrow if I will go with a 350 or 383 crank kit for my rebuild. Originally I was going to go with a 396 kit, but with the cost of premium unleaded at over $3/gal and 120mi round trip 5 days a week, the fuel cost will be too high.
Kit will have forged pistons/rods, cast crank. I have to choose between 10.3:1 and 11.1:1 pistons in either kit.
I will be adding the GMPP LT4 hot cam kit, lightly ported stock heads, and MAC headers/y-pipe with 3" OR exhaust into a 2-chamber Flowmaster.
I am going to use Denso semi-lead proof O2 sensors so I can run AV/race gas occasionally.
Can I get away with the factory ECM cals safely ?....no money for custom programming exists right now.

 

Stock injectors will hit 100% duty cycle at 430 flywheelHP. If that's enough power for you, you can use them.

The rest is pretty much basic LT1 Engine Tech, so I'll move the post there for you.

 

all I know is I used #30 Ford SVO's and with a 383 and a bigger than average cam, it was running too high of a duty cycle, on stock fuel PSI, I dont want to turn the fuel PSI up, so I went with a set of racetronix #37 injectors, this should do me fine and I should never need an upgrade.

 

I wouldn't build a 383 and run stock programming; both performance and fuel mileage will suffer. Worse yet, you could damage your new setup from detonation. Programming is a poor place to cut costs in the budget.

 

It really makes no sense to invest a lot of money in an engine build, then poor-boy the fuel and tuning. With a bad tune, you could max out the stock injectors at 400 flywheelHP. And its really not a good idea to push them over 90% duty cycle.

For a "ball park" on required injector size (assuming you are sticking with the stock fuel pressure), multiply flywheel HP x 0.07

Example 450 HP x 0.07 = 31.5 #/HR

That represents approx a BSFC of 0.48 #/HR/HP, and an 85% DC. This is for normally aspirated engines only.