Re: anyone swapped 6cy to 8cy and regret it?
 

I was lucky to get 10-12mpg on the highway or in town (not much difference) with my 250.

All I can say is this: These motors are torquey as hell. If you're pulling stuff, towing or doing heavy hauling, it's a great engine. If you want gas mileage, you're not going to find it here and with a properly tuned SBC, I would reckon you'd get 3-4mpg more and for the price of less than $1k for a crate motor, it's a good deal.

I'll also add this: I was running with a 3spd on the column, and I reckon if I had a 4spd on the floor or a 5spd with my 3.73 gears, I probably would have been a little more efficient on the mpg. If I were to do an inline 6 again, I'd install an automatic tranny and I could probably have been happy as hell with that. Just my 2¢ ☺

EDIT: I saved my original inline and sold two other ones recently. I hate to see them go out to scrap. They are expensive as hell to rebuild, and most people want a newer engine, and when you see it's gonna cost $1500 to rebuild properly, it's wiser to buy a SBC in a crate. It is also 100,000 times easier to find parts (quality parts, that fit) for an SBC versus an inline. Finding custom headers for my 250 was a NIGHTMARE, then I had to take a ballpeen to them to get them to fit, then they hung too low! Pics of the fitmet and everything are here: http://satellitehead.com/gallery/thumbnails.php?album=8

That's a common issue! Be prepared to deal with it if you keep your inline! Aftermarket performance parts for inlines are 2-3 times more expensive as well. Start talking about customized/ported+polished heads (lump port mod, etc.), you're talking about $2-3k right there. Sucks!

All this has led me to put a newer LS1 into my truck. Swap is stalled right now, but lots of progress has been made. Pics are here: http://satellitehead.com/gallery/index.php?cat=3

Re: anyone swapped 6cy to 8cy and regret it?
 

I love the 383 but everytime I see a old straight 6 I want one!

Re: anyone swapped 6cy to 8cy and regret it?
 

http://www.67-72chevytrucks.com/vboa...d.php?t=207788

having a very similar debate in another thread about gas mpg, I think there is a lot of potential in the I6's because of all the torque mentioned, and the smaller displacement. Someone mentioned towing, recently I pulled a 3/4t 4x4 on a dual axle trailer home over 300 miles with my 250 I6, I think with a crate sbc, I would have had to pull the RPM's a LOT higher than I did on my I6....run it up to 2k, let the clutch out nice and slow, and you can even pull up a decent grade from a stand-still! This engine has quickly won me over, and I have no plans of trading up/down (personal preference) for a V8 anytime soon.

Re: anyone swapped 6cy to 8cy and regret it?
 

I have a 70 GMC 1500 with a 250 in-line 6 and a three speed. Not sure about my rear end, but going over 65mph makes me uncomfortable listening to the engine, so my guess is it's geared pretty low. I use the truck to drive 6 miles each way to work and back on country roads. I get 17 mpg or so.

I have a 66 Chevelle SS396 for speed, so I'll be sticking with the 250 in the truck. It's got plenty of power for my needs, and I can't complain about the mileage.

Now if I can only find a P/S bracket to fit my 250... Any ideas?

Re: anyone swapped 6cy to 8cy and regret it?
 

Subscribe and post a wtb thread on the parts board.:D

Re: anyone swapped 6cy to 8cy and regret it?
 

I am really torn over what engine to go with when the time comes. Right now, I have a 230 w/ 3 on the tree, and I get 20 mpg. But I don't win many races. Sometimes old VW vans pass me on the hills. I have a 327 to rebuild, and a 250 mercruiser. That boat motor is supposed to make lots more HP than a normal 250. Right now, I am leaning towards the 250 / 700r. Next week it'll be the 327.

Re: anyone swapped 6cy to 8cy and regret it?
 

What year is your truck? I thought the 230ci was on the older 60-65 trucks. All 67up got at least a 250. I know they are the same family.

Re: anyone swapped 6cy to 8cy and regret it?
 

My 67 panel used to get aroudn 16mpg highway, 13ish city before that lil sixer blew. Top comfortable cruisign speed was right at 60mph, otherwise that thing was screaming, It'd do 75-80 but didnt like it :) I get the same or better economy out of my 350 than the lil sixer so to me I'd rather have a 350/auto that'll pull like a 6 down low and even better on the top end.