Thanks Supermag, That is an excellent point on Miles per Dollar.. As far as that goes, I am winning right now.. Getting propane at about $1.50 less a gallon.
I was running a stock, tired six on Gas before I put in this new powertrain. It had enough power, but got between 12-15mpg itself on average, in large part to being really tired (no compression) i suspect.
My current gearing stays, so does the tranny. Third at 60mph: 2800rpm. Overdrive at 60mph: 1600rpm. I would never use overdrive if I had taller gears. Currently I only run 30 inch tires. If I was to move up to 33's, I'm pushing rpm lower, and was considering moving taller to 4.56, if anything.
I do know the AOD eats about 20hp, but it stays too. I spent over $2000 having it built specifically for the truck. If it does blow anytime relatively soon, I promise to give up on automatics altogether in disgust, and will put in a ZF 5 speed, I promise!! (promised that to myself after paying the bill, actually!)
Do I want much? sure.
Getting back to it,
Does anyone figure I'd gain much compression merely planing a head?
Any thoughts on changing the rocker arm ratio?
I'd like to get a good idea of what possibilities exist through head-work alone at first. I will begin working on building my block in the new year, and am thinking about FE pistons, and an RV cam for it.
Doing the head first (along with intake/exh) I figure will help me to gauge what I should do to the block when the time to pick parts comes.
If at the end of this, i still make 12mpg, but 25% more power, well that's alright too. Ideally though, I'd like to achieve a 20% increase in fuel economy, and maybe a 10% increase in power.
Again, I figure being underpowered is half of what's hurting my six's economy at this point...
Thanks again for all the insight. I have saved the earlier responses, and am in awe of the responses from fellows like Xecute and Slow. I think, in terms of what xecute has said, I dont want crazy compression, but I think I have 7:1 right now, and am thinking being closer to 9:1 would be ideal.