I've got the 36lb Fast injectors from a head/cam built. I'm looking to build a 408 stroker and most the calculations I look at say that's a little small to support the likely horespower (likely 600ish at crank).

Is it possible to turn up fuel pressure to give it more flow?

 

Yes, but you'd be better off with the right size injectors.

 

Yes what G said. I will message you

 

Looks like 42lb injectors are recommended.
This is an NA build. Does the fuel pump need upgraded?

 

For this I would recommend upgrading the pump too. 42 sounds a little small, but that's assuming they're 42 @ 58 PSI. Best way to know for sure is to talk to a tuner that can scan injector duty %. Shoot for about 80-90% at WOT. With bigger cubes, heads and cam, 42 just sounds a little small. Hard to say without a log.

 

He would need at least 42lbs injectors @43psi.

 

Yeah that's what I figured. That would mean they would be 60's at 58. Sounds more appropriate for that setup.

 

You should need 40-45 lbs injectors for this purpose

 

Fast 36 injectors are 42 psi with 58 psi at the rails. I'm making 550/502 whp with those injectors, racetronix 255 and hot wire kit (62 psi at the rail). WOT, duty cycle is 87-94%. This is an LS3 427. About to drop some 80 lb injectors in for future upgrades.

 

You should always stay out of the 90% + Range. 80% is where you want to be. 42lbs injectors @43psi will get him around the 80% mark, which is why I said "at least" 42lbs injectors @3BAR