LS1 swap into a 94 Z28?

i wanna make my car fast this summer for the least amount of money. my buddy still has that LS1 for sale and he gave me the K member from it along with the whole front suspention, and his motor has the complete wiring and computer. i know that i would need a new bellhousing for my tranny and a different clutch, but other than that how much more work is involved? considering the initial cost of the motor complete hes asking $1800, how much more money would i need to get 400rwhp? its got 98k and i dont know much about the reliability of LS motors past 100k, so im not sure slapping a big set of heads and a big cam would be smart, but it runs perfect. i figure a forged stroker rotating assembly for my LT1 would cost around $1900(i know i dont need forged, but when money comes id like to put on a nice set of heads, maybe some nitrous), add in the machining of the block and stock heads and intake and stuff and thats around another $2000 at least probably, and i still am not sure if it would make more power than a heads/cam LS1 non stroker. another factor, however lame it is, is gas milage. its 500 miles one way to school, and i dont wanna be getting 10 miles a gallon the whole way (did it for a year with my old truck, NOT worth it). i have a complete LT1 with 88k sitting in my garage from the car i tore apart over christmas that runs perfect also. basically, im looking to find out hp/dollar and reliability which would be better? if both of these ideas are stupid and someone knows an easier one to get 400rwhp reliably, tell me. thanks.

You can get 400 at the wheels or close to it from the LT1 with a good heads/cam setup and supporting mods and spare yourself the hassle of doing the conversion.

You are going to need an LS1 T56 to go with the LS1 motor. You cannot just change the bellhousing and clutch. The input shaft length is still different, and that requires the whole trans being disassembled.

The LS1 engines are reliable beyond 100k, but like any other camshaft swap there is a chance it will spin a bearing. For what you said you might spend, I would just up the LT1 versus the LS1. LT1's can reach 400hp fairly easy too, LS1's can do it cheaper though since they have more power to start with. The LS1 is going to need a new trans so that's another 2000+ dollars. Going by what you said...

LS1 = 1800 (for engine) + 2000 (for trans) + 2000 (for heads/cam)
or
LT1 = 2000 for heads/cam

im just nervous about puttin heads/cam on a 88k motor or even on the 109k motor thats in my car now, both run fine but i cant have things breaking when im at school. so if i did the LT1 buildup id need to rebuild the bottom end.

Just do the compression test. And if it's fine.. than you are fine! 100k not that much.
Good Luck!

Plenty of people do heads/cam installs on higher mileage motors. One of the main things to do during the install is keep everything clean. People usually take out bearings soon after by carelessness while installing everything.