Post your cruising rpms @60mph

[79Betty]

79
350 quadrajet
All stock
4.10's
35x12.50's
10 city 13 highway @ 2500 rpm
Would get better if i'd keep my foot out of it lol
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[Skunksmash]

Originally Posted by Blackpony

Hehe



Ehhh I probably have around 4k in it. My biggest expense though was I bought the parts little by little as I had the cash and found a deal. I completely rebuilt my engine, new pistons, rods, crank, cam, springs etc. it was a new engine when I installed it. Also I bought a fully built trans and new converter. If you go 5.3 take out and can get say an engine and trans with the accessories and wiring, you should easily come under 2k total. I was just picky and wanted the aluminum 5.7 rather then an iron block so they tend to me a bit more expensive.
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Yeah I could get an all aluminum 5.3, but the difference in weight is only 40lbs. Still might do it, don't know. Putting spark plugs in aluminum heads may not be stress that I want in my life. Unless they got smart and started making that part iron. Then again, maybe the iron blocks still have aluminum heads...

[Blackpony]

Originally Posted by Skunksmash

Yeah I could get an all aluminum 5.3, but the difference in weight is only 40lbs. Still might do it, don't know. Putting spark plugs in aluminum heads may not be stress that I want in my life. Unless they got smart and started making that part iron. Then again, maybe the iron blocks still have aluminum heads...

They actually make an all iron ls engine. cant remember the year but it is a 6.0 and usually they are in 2500 hd trucks. There should be no reason to change plugs but maybe every 2-3 years unless you drive a bunch. 50k on a set of plugs is normal life. There is 0 difference in putting plugs in an aluminum head over an iron head. Our shop car gets new plugs every 2-3 passes down the track. With 1300 hp you have to keep fresh plugs in so you dont burn up the engine. we are yet to have an issue. Also the aluminum block is around 65-70 lbs lighter then its iron counter part.

[eray92]

I'll porbably sell the 4.56 gears to some pretty cheap and try to trade my 20s for some 15 wire wheels that will raise my rpms up a bit
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[Gregs71]

87 st cab long bed 4x4
350tbi /th400 / 4.11 grears at 55mph= 2400rpm= 8mpg


89 crew/dually 4x4
454tbi / th400 / 4.11 gears at 55mph=2400rpm=8mpg

Need to add an OD!!

[wraprail]

85 C10
Stock 305 Headers
T56 .50 6th
29" tire
3:70 r&p
1600@80mph
No idea at 60mph, who drives that slow?

[eray92]

Originally Posted by wraprail

85 C10
Stock 305 Headers
T56 .50 6th
29" tire
3:70 r&p
1600@80mph
No idea at 60mph, who drives that slow?

1326@60
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[makman1297]

77 K10
350 TBI 700R4 NP 208
StarFire 285/75R16
4.10 Gear Ratio
1750 & 60 MPH
Gets 16 MPG on long cruise.

[Corts60]

'78 short box 2wd lowered

350 Diesel,t400,GV o/d-.78 final drive, 3.40 in the rear. With a 27" tire I was at 2300 RPM at 70 MPH and if I drove all highway I got 23 MPG. 18 MPG in the city

I just swapped in 3:73's with limited slip in the rear which should put me around 2500 RPM at 70. We'll see what I get this next week for fuel mileage.
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[Rubble]

Originally Posted by Keith Seymore

Tell him about the MOPAR A833 manual overdrive trans that you could get in these trucks....

http://www.customclassictrucks.com/t..._transmission/

K

I have the same tranny in my 82 K25, 6.2/833/208/3.73.. It's howling a bit in OD,but it still gets 20mpg on highway in 3rd at 60 mph. Not bad for a 6" lift on 35s . 22-2300 @ 60. I like this tranny better than the 465, lot shorter throws too..
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[Rubble]

86 K20 350/465/208/4.10s 7" lift on 35s runs about 2500 rpm @60 about12-14 mpg
81 K35 CCLB 454/400/205/4.56 rpm unknown,6-8 mpg.
86 K25 6.2/400/208/3.73s 4" lift on 33s runs about 2600 @60 about 16-18 mpg.
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[slugish]

Originally Posted by INSIDIOUS '86

26.5 tires and 3:73 gears and th350. 3000rpm at 60mph 3500 at 70mph which is where I cruise at haha. I need a nice 200r4
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Yea, I had 373 gears & a 350 3 sppeed at one time , & youre right on at 3000 rpms at 60 mph . Too steep for me , put in a 3.08 ,didnt like the performance , ended up with A 342 (BOUT 2500-2600 RANGE AT 60) Still not great over 70 , but I got tired of throwjng money at ring & pinions , plus the labor of someone else doing the work. Oh well you live & learn . I did a lot of things to my truck before I GOT ON THIS FORUM . yOU ARE SMART IF YOU GET ADVICE ON THIS FORUM, LIKE A LOT OF YOU ARE DOING, BEFORE YOU MAKE YOUR MODIFICATIONS

[Keith Seymore]

Sorry to be joining so late, but I've been away on business and haven't been driving the truck.

Looks like about 1900 rpm; 4.3L V6, MY6 manual overdrive trans (.73 ratio), 3.73 rear axle, P235/75R15 tires.

K

[gchemist]

ZZ4 355 HP!!!
700R4 custom built
3.08 gears
255/60R15
1950 RPMS @ 70 MPH
18.5 MPG :METAL: