tell me about inline six/I have some question

[dilling]

What kind of mileage do you get ?
What rear end ratio does your truck have ?
Auto/maunal ?

Are there any good auto that bolt one easy ?
Does it share the same pattern as small block ?
How hard is to find brackets for ps/ac ?

I want to keep six in the truck, but if it is hard to get bracket for ac.ps I will swithc out ?

[davidh]

I just bought a parts truck that has a 250 6, power glide, and power steering, Kind of rare for then. The 250 6 in good tuned up order should get you about 15mpg with a 3speed 3.73 rear end.
I've been talking to a tom who has a inliner parts page. If you want mileage you need to use HEI and a 5speed T5. His company sets them up with S10 casing and V8 internals. He has a 72 and gets 19.5mpg with it. the tranny cost btw $500-700. I plan on running a inliner in one of my old trucks.
I had a 67 250 3speed a few years and liked it. I would've kept it if the dash had not been all hacked up and idiot PO had spray canned over the original paint..
If you pick up 3-4 miles a gallon with the 5speed. At around 2.25 gallon it would take you give or take 100 fill ups(15-16gallons) to break even approx. Depends on how much you drive to justify the big purchase of the trans. 3speeds go for $50 usually

[shifty]

I had an L6 in my truck (250) with a 3spd Muncie tranny on it (3 on tree). I seriously averaged less than 7mpg with that setup on 3.73 gears.

I will tell you this, though: That damned engine was the easiest thing EVER to work on. There is literally almost nothing that can go wrong with it. Upgrade the stock points ignition to HEI ignition and it starts every time like clockwork (one tap on gas, then turn it over and BAM! it was running).

Bad part: good bolt-on headers that FIT well do not seem to exist. Tolerances are very tight in there. There are good bolt-on intake manifolds out there for the L6 though. 292 seems to have a lot more options, and more potential as well.

[davidh]

this guy Tom I refer to worked at GM for 35plus years. He said the 250 3spd was designed to make 15mpg. The other factors are big, wheels, tires combo. I plan on keep this one pretty much a stocker. If I get 16mpg with HEI and all tuned up I'll be happy. My 68 when it had auto, 350 2bbl and points got 8mpg in town!!! 14-16 would be great to that.

[shifty]

I had 15" wheels with standard sized tires for those wheels. I upgraded to HEI, but put open headers on at the same time and still saw an increase of 1mpg roughly. Highway driving with the 3spd killed me because at 65mph I was running too many RPM's to be very efficient. 8mpg was max I would get. I have no idea about city driving. Not very feasible to do much stop and go with 3-on-tree, no power steering and in heavy traffic.

[TP from Cntl PA]

I have a 250/4spd in a '72 K-20 with a stake body(Weighs more than a stock box).

I posted over on the inline board about being impressed with the mpg of it. This same engine was in our '69 C-10 Farm truck. The guy who owned that truck before us road the wheels nearly off of it since buying it new. All it ever had done to it was a valve cover gasket, and we did have to pull the pan after the threaded plug inside the pan broke its spot welds and turned, so we couldn't get the oil plug tight. We took the pan off and welded the insert and re-installed it with a new gasket. We tore that old truck apart, and I took the engine, painted it, and dropped it in my K replacing the 454. I added a Clifford 4 brl water heated intake, Clifford truck headers, Edelbrock 1404 500 CFM carb, made a air box to use the air cleaner off a V-8 which moved it over top the valve cover. Nothing but pipe and a glass pack for exhaust which dumps infront of the rear wheel on the drivers side.

Anyhow, after some initial troubles getting it tuned, the guys over at inliners.org helped me out and I was able to get her running right. We've been driving it alot and its probably the best truck we have mpg wise other than the one with the Cummins. I don't know what gears are in this truck, but she runs pretty good down the interstate, but still is low enough I don't have to drop down to 3rd very often on hills. I can't say what I am getting with the 6, but I was getting 10 with the 454, and its WAY better than that judging by some of the places I went, remembering how before with the 454 it took a 1/4 of a tank, now the gage barely moves. Since I am not the only one running it daily, its hard to check fuel mileage which is why I haven't yet.

I am going to eventually swap this engine out for another Inliner I am going to build up. But I may run this one until it gives up, but going by our past experiences that may be a LONG time.