HOW CAN I MAKE IT GO FASTER?

[Avery brown]

My truck is a 74 it is a 3/4 ton it has a flatbed on it and it is the sm465 4 speed manual with a target master 350. The top speed on it is 58 as of right now and i want to make it go at least 65+ I wanna know every possible way to make it go faster. And yes i want to have 265/75/16 tires. Any help is appreciated. Thanks!

 

[PrairieDrifter]

Bigger tires
Regear
overdrive unit
transmission swap

Those are your options. A regear is what I would choose if I were you.

 

[77 K20]

Should be able to do 65 easily right now. What RPM at you turning at when you are "topped out" at 58 mph?

You sure your engine is running right? (proper tune up, good compression, cam lobes not wiped out)?

 

[AyWoSch Motors]

I'd say make sure everything is functioning the way it should. Make sure the engine is up to par. After that, change the rear gear. If you have 4:10s or something, itll be screaming.
I have a SM465 too, but it'll do 100mph without much issue. As long as the engine is running well, and the rear gear isn't something crazy, I don't see why it shouldn't do 65-70 easy.

 

[Ricko1966]

Put it on a rollback that will go 70, problem solved. Your welcome. Sorry, couldnt resist. I think before any of us can help you, you need to find out what rpms your turning at 58mph and what rear gears you have. As for every possible way to make it faster, there isn't room to write all that. Stick with the basics, a healthy engine, and the right gearing.

 

[nvrenuf]

That tire it 31” tall, you should easily be about to run 70. Even if you have 4.56’s you’d only be running 2700 rpm at 55 mph.

 

[Grit dog]

^What he said. With your tires and a 1:1 top gear, you're at 2500-2800 rpms at 58mph, if you have 4.10 or 4.56 gears. If you have taller gears then even lower rpms.
The issue is 100% under the hood if that engine can't push the truck past 60mph, or 70+.

 

[Catbox]

Mine has 265/75/16's and the SM465 and runs 80 mph on the highway like a champ.
I do have a set of 3.73 gears in the rear end.

 

[Catbox]

I would say check the tune of your engine.
That and vacuum leaks.
Simple and very effective to make things better.

After that, how is the engine configured?
Single exhaust?
Plugged catalytic converter?
Mis matched hot rod parts on it?

Tell us more about what you are working with.

 

[Bruce Wingate]

Might sound stupid, but make sure the gas pedal can go all the way to the floor. No bunched up carpet etc. And is the accelerator cable long enough?

 

[73c20jim]

Check wide open throttle.

 

[Matt69olds]

Do you have a tach? Not that it matters much, even if the truck had 5.13 gears it should run better than 60mph.

My first thought: exhaust kinked up or restricted? Fuel pump or fuel filter/lines restricted? Engine tune?

 

[RecklessWOT]

Bigger tires
Regear
overdrive unit
transmission swap

Those are your options. A regear is what I would choose if I were you.

Couldn't have said it better myself

 

[swilson143]

My truck is a 74 it is a 3/4 ton it has a flatbed on it and it is the sm465 4 speed manual with a target master 350. The top speed on it is 58 as of right now and i want to make it go at least 65+ I wanna know every possible way to make it go faster. And yes i want to have 265/75/16 tires. Any help is appreciated. Thanks!

LS swap!