anyone swapped 6cy to 8cy and regret it?

[shifty]

Originally Posted by davidh

so, am I guess 15mpg out of bean and thatoneblue67?

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

[67chevemall]

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

[shelby987]

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.

[kuma]

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?

[krue]

Subscribe and post a wtb thread on the parts board.

[pritch]

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.

[davidh]

Originally Posted by pritch

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.

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.

[Josh]

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.