looking at the aftermarket TPI wiring harnesses to retrofit a 1990 speed density system into an older car. any advice? recommendations?

I see that Painless Wiring sells a harness, Howell also. not sure if there are others.

I intend to use the 7730 ECM since I already have the chip-burning capability for that.

 

I can help you with your project. We frequenty build new TPI harnesses for custom vehicles. If you're interested, please email me at mike@eficonnection.com.

Please include:
- desired length from ECM to back of engine
- desired length from ECM to diagnostic port
- whether torque converter lockup (700R4) is required
- number of electric fans
- 3 wire heated O2 sensor or single wire O2 sensor

Thank you
Mike
EFI Connection

 

I've used a TPI harness and OBDII harness from eficonnection(S10Wildside). Quality pieces. Trust his work.
Ron

 

I just used a Street & Performance harness to put speed density TPI in my 66 truck and thought it was very well engineered. Not cheap though.