OK Guys need some help... He is want I got.. 1965 c-10 shop truck full Porterbuilt deal.. my whole combination is off... .030 327 10-1 speed pro pistons / 2.02 461 heads. full comp cams valve train with roller rockers / Comp. mutha thumpr cam 295TH7 Trick flow street burner intake duel plane # tfs-30400222 Holley Billet ultra fuel pump... have 3 differant carbs from a new Street Demon goggle valve 625 cfm, quick fuel 650 hot rod series / Holley ultra street avenger 650CFM full MSD ignition with box... 1997 t-56 six speed with a 4.11 posi unit 31.5 inch tall rear tire.. This combo does not work will not pull it in 5 or 6 gear whats wrong...
Yeah, you need something that produces lots of torque at low rpms. That's usually big cubes/long stroke, not a short stroke 327... Think Caddy 472, 500... r
Could probably get away with just a cam swap. Valves are pretty big, but changing that is spendy although you could probably find a bunch of street racers that would swap heads with you.
Yep, The cam is all wrong for towing. That's a common mistake, building the "cool' thumper engine for your rig and then not being able to do what you really need to do with it as it's all wrong for the job. It no doubt will impress the mouthbreathers down at the burger joint on Friday night when you rump rump thought though. The reason we know it's wrong is that we have all done it at some time or other, I pulled a 16 ft U haul trailer loaded with everything we owned behind my 48 from Texas to Washington state running a 283 with a 30-30 Duntov, Muncie M21 and way too tall gears in the rear end and it as pure hell for 2500 miles. The damned thing ran 80 mpg at 3000 rpm and got 18 mpg with N 50 14 tires on the back when it didn't have a trailer on the back though.
"Will not pull in 5th or 6th gear" do you mean towing as was said above or just a seat of the pants feel. What RPM and how fast are you going at that gear change. It would seem that there are a few more criteria that need to be taken into account here. I had a 70 3/4 ton suburban with a 30 over 327, Schnieder cam (mild) 1.94 heads and a 2bbl carb on a stock manifold and it ran and pulled up to and past 70 MPH easily never went past 85 MPH. Exactly what are you expecting? Have you run it at the track? I think there are still a lot of questions. But I don't think you need to swap it out for a Caddy either. Pat
Go the junk yard or get a re-manufactured and mid 70's 292 Chevy Inline 6 and put a 4 barrel intake on it with headers. You'll be able to pull and cruise pretty good and get better mileage than a v-8.
Mini motors spin to make power. RPMs are needed to make it pull. Are you trying to haul real payloads/trailer?
Too much cam, pure and simple.... They list the RPM range as 2500-6500 which means below 2500 there won't be any meaningful power. You need a short duration (no more lumpy idle) 'torque' cam or steeper gears to pull those overdrive ratios.... Go with a roller cam for best results.
Have you checked a ratio calculator? 6th gear is .5. With your set up, you are turning less than 1500 rpm at 65 in 6th. Your cam is either too big, you need to switch tires, or change out the rear gears. Other option is to just stay ou of 5th and 6th.
A torque (that is what pulls/pushes weight) cam (smaller) is needed. Cam companies charts that give basics. Really, 6th is for top end cruising not pushing you back in the seat. That is what 1-4 is supposed to do. You should be able to sustain 125 MPH+ w/the present combo.
I'm not familiar with the cam, but the others here say it's too big. I say the carbs are all too big. That motor, unless your way up there in the RPM range doesn't need anything more than a 500cfm carb. I don't think you have anything wrong with your gearing, you would have to be going super fast to be "on" the cam in 5th & 6th. My 2 cents: you need an RV cam, off idle to 5500rpms. Remember, torque gets you moving, horsepower keeps you moving. You won't believe what a difference changing the cam & carburetor will make.
Too tall of tire or not enough gear 5.38 gears would put you at 70 mph at 2000 rpm right now your at 91 mph at 2000 rpm with 4.11 gears
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