do a compression and or leak down test. if all goes well your engine should actually take more than a 55 shot for some time.........and as far as tuning its rather hard to explain but heres a good read
http://www.musclemustangfastfords.co...8mmff_nitrous/

 

Ok what I got so far:

[ul][*]
Compression Test[/align][*]
$599.95 Wet Kit: Link[/align][*]
$43.95 Nitrous Gauge & Mani: Link[/align][*]
$104.95 ZEX Nitrous Purge Kit Link[/align][*]

$16.00 Autometer a/f Ratio Gauge (E-Bay)[/align][*]

$40.95 Autometer Fuel Pressure Gauge (E-Bay)[/align][*]
$12.99 Glowshift Duel Pillar Pod Link[/align][*]
Replace plugs with 1 step colder[/align][*]
Replace plug wires with newOEM wires[/align][*]
55 Shot - No Timing Retard (If I ever go 65 shot then 2* retard)[/align][/ul]
Anything else that needs done?

 

http://cgi.ebay.com/ebaymotors/ZEX-8...spagenameZWDVW
cheaper zex kit......and it comes with a nitrous book you can read for tips and tricks.