Lower pop pressure will advance your timing. Your turbo engine most likely won't like the lower pop pressure and too far advanced timing can cause problems and even engine damage.

Can you tell us why you think your IP is weak? If you have verifiable IP issues, the cheapest option is usually to source a good used one at a junk yard, etc. Still, it's not common for an IP to fail on a 617.

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1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge