Besides a V8, what do I need to do to make my Chevy straight six with a stock 4 speed a highway cruiser. 65 mph would make me happy and 70 even happier. I've seen gear kits and tranny kits as well. Any info would be appreciated.
3.0x rearend gears would probably do the job. 2.7x would definitely make it cruise nice, but will be pretty sluggish off the line. and make sure it's a wide ratio 4 speed.
When the car/truck was built, 70mph was the speed limit so if tuned correctly, it should do it no problem. If you want lower RPMs then change out the rear axle to a 3:00 like I did. Put taller tires on it too. It upped my mpg but it is slow off the line. It was slow anyhow though.
Minimal info here. Sounds like gears to me. Not completely relevant but my mostly stock 235 with a PG will do 70 without any real problems. Cruises easily at 65.
If its in a stock truck, a big difference is the camshaft. Me and my parents have idendical '59 trucks. Stock 6's, 4:11's and 3 speeds, but mine has a passenger car cam. it will run circles around the other. Truck cams are made for nothing but torque. It just depends on what you have. If you have a granny low, you can put a real high rear gear in it and it will work well.
I took a 3600 mile trip last summer in my '37 Chevy coupe with a 235, 3.73 gears & overdrive in the torque tube. We drove out & back on I-90 with the majority of speeds at 70mph. Got an overall 23mpg.
TagMan I want to hear more about the OD with the torque tube, I did not think there was one available....Where did you get it and how much???
It is a truck with a granny low; basically stock everything. I saw 3.55 gears in Patrick's for $399 then an install kit for another 299. Honestly, I don't know what gear sets go for so I am using this as a comparision. I am wondering what would be cheaper and or easier and or more in line with my desire to take the truck on long trips - replacing gears or rear end, drive shaft and tranny.
I ran a 235 w a powerglide and 3.55 rear gearsin a 54 more door, cruised at 65 no worries now I'm building a Model A w 235 or a 261, running 3.78, and it'll cruise at the same rev range due to taller tires, approx 2400 rpm
oh....... do those trucks have open driveline? it's not a chevy, so don't get too excited about the parts you can buy for chevys, first figure out what rearend is in it.
If it's a GMC engine in reasonably good shape, then it'll run forever at 70 mph with a 4.11 axle & 30''-31'' tires. If it's a Chevrolet, you'll either scatter it or wear it out a lot quicker. Don't confuse the two engines, the GMC is much stronger down below.
I got Patricks 3.55 ring & pinion for my stock tranny and torque tube in my 52 truck with late 235. Daily driver since '95 and often goes on longer freeway trips around 3000rpm at 70mph, for hours all day. It was expensive but with todays gas prices, well worth it. Gets 18-20 mpg and the engine was rebuilt last over 20 years ago... On my 48 coupe I am replacing the torque tube and gear section with the same of a 54 powerglide car. It fits straight into the original 40s rear housing with original axles and wheels. Same end result as with my truck, just at 1/10 cost. Most chevy 6 drivers I know about like the later open driveline which has several modern tranny and rear ratio options.
Sounds like a little gear change is in order here, something around 3:00 ratio would make a world of differance, might be differant if you have a granny gear tranny. But should make it cruise 70 with lower RPM.
HOLY SHIT! That I didn't know. I've got a '59 261 in my 53 sedan. Now you've got me wondering about cams. Great thread!
dont be afraid to put some gear in it . the 235 has lots of torque and will pull a lot of gear. i had a 245 final in overdrive and 3.36 in straight 1 to 1. at a minnum i would use 3.00 and maybe 2.73.
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