95 olds 88 engine swap problems

in need of help wit a few issues...i installed a 3800 series 2 engine from a 98 olds intrigue in a 95 olds 88. according to interchange the block shoud work so i set out to get her done. the old engine had a different intake,throttle body sensor,egr and exhaust setup so i exchanged the plug in wire harness from a 1995 park avenue to match. before i took out the old engine it would crank and barely run. now after install i have no crankin,no fuel pump, no head,interior or tailights. check engine and hot light sometimes flicker on and off when ignition is off...its my friends buddy car so im not sure if the light worked before or not??? i need help on what could be wrong or what i di?? ive done this before with no problems so im not sure wassup.. it shuldve ran