71 f100 prerunner

[LENNY]

Thanks Disaster Have you heard when the rer fenders will be ready,Ill keep in touch as I get this truck prep for a Baja run,

[SPONSOR]

Membership in the largest desert racing community has its advantages - Participate in Forum Discussions - Send and Receive Private Messages - Maintain Public Photo Albums - Access to Groups - User Profile in our Social Network - Increased Access to more Sub Forums - Reduced Online Advertisements Join our community today

[99tmsmith]

What size motor do you have in your f 100?

[Dezertdisasters]

What size motor do you have in your f 100?

It's a 400m turd for now, hopefully it will last this season and than I am leaning towards a ls and a 4l80.

[LENNY]

It's a 400m turd for now, hopefully it will last this season and than I am leaning towards a ls and a 4l80.

DD whats the wt on your truck,just put mine on a scale and shes 5400lb,ive got a 400m with a edelbrok and im seeing 3 1/2 t0 4 mpg,I dont think a LS 3 has enough tq

[atomicjoe23]

If built for the application an LS3 would do just fine. . .lots of articles floating around out there with LS3 builds, they'll make as much torque as you build them to. . .

. . .even a 5.3L LM3 will put out enough torque if built correctly.

[LENNY]

What kind of milage will a LS get

[atomicjoe23]

Since I don't have one, especially not one built for racing I don't know what an off-road racing LS will get, but the stock Corvette tune gets about 22 MPG on the HWY if I remember correctly. . .

. . .I'm sure under race conditions and built to race spec's that the mileage won't be much better than anything else out there, but there would be a significant weight savings vs. an iron block engine.

I'm sure one of the LS guys would be happy to share what their mileage is like. . .

[Dezertdisasters]

DD whats the wt on your truck,just put mine on a scale and shes 5400lb,ive got a 400m with a edelbrok and im seeing 3 1/2 t0 4 mpg,I dont think a LS 3 has enough tq

The trout is 4976 with a full tank of fuel, but still have a few things to add so I think it will be right around 5500 all said and done. And I could be wrong but I am pretty sure a 400m never came with over 300 ft pounds of torque from the factory, so even with a small cam, intake, 4 barrel carb and headers it will still be quit a bit under a stock ls3. And my 400m seems to start falling on its face before 5000rpms. I am looking at getting a lq9 junk yard motor, and throwing a cam and maybe set of cnc ported l92 heads, they are pretty cheap and make great power numbers. And with the fuel injection it would have to be a lot more efficent than a 4 barrel carb on fuel.

[atomicjoe23]

Those M motors are pigs when it comes to weight too. . .I've got a 351M in my '79 and a 400M sitting in the garage; that 400M weighed as much as the 429 sitting next to it!

[BRINGTHERUCKUS]

Our prerunner has a 400M and that thing runs like a raped ape. some good head work, cam and timing will allow the motor to open up and make really solid power. I would also say the same about our stock full but im not sure its actually a 400...