4L60E option or just go 4L80E

[jgreen16]

I currently have a '90 RCLB with 350 TBI with 700R4, that I plan to do an engine upgrade on. No LS swap, just a more stout 350/383 with a target of 400 hp/400 ft. lbs. I've never been a fan of the whole TV cable setup with the 700R4. Part of the plan with the new engine is to go with a Sniper 2 of Edelbrock Pro-Flo EFI system, so I may as well just go with a transmission controller. The 4L60E doesn't require a change in driveshaft length which is good, but would it just be better to bite the bullet and go straight to the 4L80E?

 

[NickTransmissions]

I currently have a '90 RCLB with 350 TBI with 700R4, that I plan to do an engine upgrade on. No LS swap, just a more stout 350/383 with a target of 400 hp/400 ft. lbs. I've never been a fan of the whole TV cable setup with the 700R4. Part of the plan with the new engine is to go with a Sniper 2 of Edelbrock Pro-Flo EFI system, so I may as well just go with a transmission controller. The 4L60E doesn't require a change in driveshaft length which is good, but would it just be better to bite the bullet and go straight to the 4L80E?

If you're doing a 383, just go with the 4L80E. Rollerize the rear of the case, dual feed the direct clutch internally and drill the spacer plate clutch feed orifices per application and converter stall. If a stock to about 2200 stall, open the direct feed to .080, overdrive feed to .075 and leave the 1-2 feed alone. Set intermediate clutch clearance to between .045-.050. Install the Sonnax TCC regulator valve and test the AFL valve for sealing integrity. It's common to see both AFL and TCC reg valves worn in the valve body on 4L80Es with high mileage.

Lastly, replace the wiring harness, all solenoids and speed sensors.