2 difficult questions about the p400: fuel economy & Injection Pump!

[fullsizeBlazer]

Hey,

need serious advice on the P 400 engine ;) , here are the basic questions I have right now:

Fuel costs really are an issue over here (very high taxation on fuel), basically - ok the dollar is low right now- you can't get a gallon of fuel without spending less than $7....

=> I've a 305 gasser (out of my parts truck), nice little engine, quite reliable, but: fuel economy: about 16 mpg => about $ 25 for 100 km driving... ridiculous. (maybe a LPG (liquified pertoleum gas) conversion would be great)

=> my old 6.2: got my around 20 - 26 gallons, quite affordable, I'm using the k5 as daily driver: well, max fuel costs about $ 19- 20 per 100 km


I do not know what estimated fuel economy a 6.5l P400 (with a th700 r4) could deliver? (w. moderate, fuel efficient driving habits of course!)

Concerning the pump & fuel economy:

is it a good idea (ok, I know, not very much power) to run the p400 as a N/A engine with a 5088 pump ?
or should i just get the whole turbo setup, and a 4911 pump right form the start ? :confused:

[rustyk]

I can't directly answer, as I have the predecessor engine, which is, AFAIK, (billet-machined crankshaft - new ones are forged) basically the same. Mine was built by Peninsular Diesel with a non-waste-gated turbo, hi-pop injectors, and a Phazer gear drive, rated at 230HP/420 lb.-ft. torque (stock was 190/370). The tranny is a 4L80E.

Mine's in a 16K lb motorhome. With the stock GM 6.5L TD, fuel economy was about 9.25 mpg. With the new engine, it's about 11.25 mpg....and that's measured over 40K+ miles.