Just added (2) Flowmaster Pn: 43541 40 Series mufflers with the first tank of fuel my mileage increased to 7.6 mpg
I just wanted to post this it made A gain in mpg and they sound SWEET!
My '71 K20 got in the 11-13 MPG range ant that engine was SHOT and I never babied it!
I have never gotten in the single did with ANY SB Chevy I ever owned that was running even half way decent! You are wasting many $$$. Find the problem and fix it before you cant afford to drive the Truck anymore! Don't get me wrong, it's always great to hear about any improvement, whether it be ET, MPH, HP, TQ, MPG...etc, But something isn't right...
ET: 13.931 MPH: 104.33
4 Speed 3.73 Posi 33 12.50 BFG AT's And I didn't say it was STOCK Cam: Edelbrock Peformer + Pn:#7102 Advertised @ .050 @ Cam @ Valve Intake Exhaust CenterlinesInt Exh Int Exh Int Exh Int Exh Open Close Open Close Lobe Seps. Intake Ctrline
288° 288° 214° 214° 0.295 0.295 0.442 0.442 0° ATDC 34° ABDC 44° BBDC 10° BTDC 112° 107°Valve train: Edelbrock Hydraulic Roller Lifter Pn:#97383 Heads: Edelbrobk Performer 64cc Pn:#60909 Pete Jackson gear drive Crank: Eagle ESP Forged 4340 Steel 400ci Rods: Manley 7075 5.750'' Aluminum Connecting Rods
531-grams 400ci Pistons: Manley Aluminum 124cc 13.8:1 4.600" x 4.250" Harmonic Balancer: Fluidamper 7-1/4'' Diameter SB-Chevy 400ci Damper Distributor : MSD Pn:#8366And I run over FORD's just pulling out the driveway I don't thank "THAT I WON'T AFFORD TO DRIVE IT" Dam it I thought I had it Dialed in crappy of MPG ????? And the AC cools 42* but it runs hot in the summer when it's 114*
Well ya need to clarify what your runnin a little...lol...
The compression is a bit high for the package. 11-11.5 would do you lots better. Going with 4.10's would greatly improve your ET and MPH on the track with the power range of the cam and improve the on street drivability too.
Toss in a set of flat top pistons for a more usable CR and a set of
4.10(or maybe a little lower) gears to help with the 1320 with benefits on the street too. I would ditch the aluminum rods in favor of a balanced set of steel H-beam rods, but I always plan on my engines going 100K +.Just a few ideas from experience...its your ride and if you like it how it is and it suites you then go run over a few F trucks in the name of alt.autos.4x4.chevy-trucks!
Have a great one!
My 79 K30. 400 small block, TH400. 4.10 gears got 6.99 MPG completely empty on a 400 mile trip. Loaded up pulling an old Fan house trailer it gave me
6.53.Al
wrong exhaust... magnaflow performance /w 3" pipes is the way to go deep throaty bark small rumble at idle and 'look out he's a mile away and closing' on throttle
bes sound overall.... 4th gear, uphill doing roughly 70 km/h sounds like it's just relaxing and purring. :D
I have never heard anything sound better than the exhaust that is on my truck and have had many people tell me the same thing
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