drfranky

What do you use for the head gasket? The old steel gasket or the telflon coated one? Do you have issue with blown gasket?

Hey Nige, these are %TPS value not KPA!! sorry I should have mentioned that! Have a good trip!

Totally agree on that FridgeFreezer. That's why I switch the 4.2 plenum that has the round TPS [these are absolutely totally unreliable] to a 4.0 plenum that has a bosch TPS and the new GM style flat connector idle valve. I just feel that the truck is more responsive on TPS rather than manifold vacuum.. As for the idle valve, I would say that PWM is probably the way to go... the stepper is nerver quite right.. some idle is at 900 sometime at 1000.. all in all, I think you guys are right, if I had to do it again, I'd go MS1 extra...

Ok, so I reduced the advance at tickover to about 10.. but the truck had no problem with 25 degree.. I have a max advance of 29 at WOT and 100 % tps. Milder accelerations tps 65 - 80 have a bit less advance I don't think that map is THAT off.. As for the 4.0 pistons, wouldn't a higher compression engine aggravate the liner slipping issue on 4.6? I cheaped on the t-top liners..

Yes, I used the 4.6 crank, wouldn't have worked otherwise.. Ok will look for a map.. but most map on the forum are for MS1, does it matter? Mine is set up for TPS (Alpha-N). Thanks for your help guys!

Built is cross bolted 4.0 block with 4.6 pistons and rods. 4.0 intake. Fully rebuilt. This is in a RRC LWB with a R380/LT230 What do you guys think of this spark map? Is it too conservative?