Quote Originally Posted by brian617 View Post
For 18psi or anything over 14psi really, you'll need more pump. The EP381 is the Vortec truck pump and fits the TBI sender very well. It's what I'm currently running in my truck at 17.5psi. I also have a EP377 which is the pump for the 94-95 30psi TBI big blocks that I'm going to try next. EP241 is the TPI camaro pump that I used originally, but didn't like the way it fit in the sender.
The EP381 fits very well, because it was designed to fit a TBI sending unit. The earlier 4.3 CPI models and the Syclone/Typhoon used this pump. It is the CPI Astro pump I have mentioned. If memory serves me right it also comes in the GM Ramjet 502 crate engine kit. The EP381 will dead head over 100 psi.