Just picked up motor and have a few questions!
 

I just picked up a 99 Ls1/t56, it's not complete but I got it home and had a few questions

1. He removed a sensor in the back behind the Intake manifold, it was not the MAP sensor in the manifold but it threaded into the block. Maybe a Knock sensor?

2. Hard to describe but at the bottom of the block, on both sides, underneath where the exhaust manifold are, there is a row of threaded holes. I have not been able to find any information on these, they are right above where the oil pan would go and have a little bit of oil dripping out. I will try to find a picture somewhere!

3. Anywhere I can get the list of bolts I need for the t56 to ls1 block?

4. I have a brand new CTSV Oil pan he gave me, but i need a GTO front sump one for my 240sx. Can I keep the improved baffle of the CTSV in just swap the pickup/pan? (anyone want to trade for GTO pan?? :)

5. On the slave cylinder of the t56 there was a little (plastic?) ring around the end, he ripped it off and told me I needed to get a new one, but didn't tell me what it was called!

Any opinions on my plans for the motor?
224 224 .581 114lsa cam (picking up this weekend, $200 with hardened 7.4 PR's.)
PAC 1218 Springs
FAST 78MM intake manifold (already have)
LT's
I know that I should replace the Oil Pump/Timing too.

Power? I'm expecting around 410whp with this setup, sound reasonable?

#1 You have the oil pressure sending unit and cam position sensor behind the intake.
#2 The holes are drains for the coolant they are a "brass" plug. Go to the dealership and have the parts guy pull up a pick of the block.
#3 Call a sponsor -----> or go to the dealer.
#4 ???
#5 Thats part of the throw out bearing. Call up a sponsor and get a 2001-2002 slave, it will come with the throw out bearing on it.
The rest of your mods sound good, I would do a LS2 timing chain, new oil pump, and lifters. As far as you 410 hp goal are you talking crank HP ?