90 240sx with 91 twin cam wiring help.PLEASE!

[lucas240sx]

i have a 90 single cam car put in a 91 twin cam motor with harness and ecu.my problem is the twin cam harness that comes through the firewall to ecu is obviously fine but the other plug that plugs into the dash support harness is different.

on a single cam the plug is white and has 13 wires

on twin cam the plug is brown and has 12 wires.

i dont want to change the cluster or dash support haness i still have my single cam plug so can anyone show me how to wire the single cam plug to the twin cam plug please because some wires are differnt colors.PLEASE HELP ASAP i need my car running.thanks alot.

[zerepdivad]

Just wire the ones taht the colors match up on the rest will be unused.

[lucas240sx]

and my tach will work and engine light will stay of?

[zerepdivad]

Tach won't work you need a dohc cluster.