Just wondering if putting a EL XR8 ECU into a eb xr8 is possible and would there be anygains from doing this.

if possible, how much work involved (is it just a straight swap?)

Not a straight swap. The EECV has alot more pin outs than the EECIV so lots of rewiring or change the whole harness. Waggin has done it, but why would you. The only possible gain is thermofan control.

Personally, Id rather put a TwEECer on a compatable EECIV ECU & be able to adjust everything myself. Some EB & ED V8's are supported for the standard model, but I reckon a TwEECer RT on an A9L (or similar mustang EECIV) would use a stock EL XR8 ECU for toilet paper. Much more worth the effort, if not expence.

Sounds like it's not worth it then.

Might go that or a complete after market then.

As Sam says not worth the effort. Besides the EF/EL basically has the same EB Cal stuck in an EECV box.
Yes and you can enable Thermofan control with the TwEECer on your EB EECIV.

Pete.