it has the 1mz-fe engine

same as mine

the avalon might come with dual throttle bodies like the es300, which mean you can custom rig a dual intake
the 5 speed from the 1mzfe camry will bolt right in

what i did to my 1mzfe:

na 97 supra fuel pump
3?? cc supra fuel injectors
port and polish
3 angle valve job
boared and ported intake and exhaust ports
boared and polished (internal) intake manifold
boared throttle body
no cat
custom y-pipe
no governor
bomz short ram intake (aem filter) (only good on camry single throttle body)
denso iridiums
ngk plug wires
ZEX 75 shot (-4 degrees timing)
built transmission (automatic)
shit i forgot
best fluids possible

my camry ran a 13.2 best time on spray at 107mph

but topped out at 162 on spray on dyno (which is funny cause speedo pegs at 140)

dynoed at 276 na whp
342 whp on spray

reliability

shocks blow fast if you drive hard

comfortability

very


thats about all i can tell you