ok..what is the factory hp and trq rating on the 76 390 with a 4bl. Noooo one seems to know! Its in a 76 f150

thanks!

 

there about 300hp at the flywheel
- about 26% for drive line losses plus a little more for age
you get about 225 at the rear wheels

225 hp in a 4600lb truck will barely peal the skin off pudding.

you right there is not much info out there on specs from 390s after 1972

 

Thanks. It has 4:10s n magnaflows so its got a little more oomph then a bone stocker.

Do you have an idea on the torque rating? I was thinking around 350-370 maybe?

 

195 horsepower NET at 4400 RPM and 376 ft.lbs of torque at 2600 RPM.

Mufflers won't do much with the restrictive log exhaust manifolds.

The truck 4-barrel intake (T intake) is actually worth 5-10 horsepower over the 390 GT (S Intake)

Josh

 

To start my truck is mostly stock. If you want a rod you have a ways to go.

Prolly a smog time set too. Not just a 360 thing. If you have the stock time set, you could get a good $$ to benifit ratio for putting in a fairly inexpensive Cloyes time set. There is only 1 part # for all FE 360/390 and it is straight up. About 50 bucks and a easygoing afternoon.
Then setting the timing. There are some real pissy arguments that come from this but this is what I found with my smog truck. GET a count down time light and use it often!!
under 100 bucks at Auto Zone.

Set time for static. Some say around 12 btdc. I have mine set at 20 btdc. I get an additional 23* from the mechanical and about 15* from vaccum advance.

Here is the bone> ported or manifold. I have a low compression engine and it burns fuel charge real slow at Idle and criuse. With ported and at idle (stop and go trafic) I don't get any advance at idle and very little at low rpm cruise down the road. I switched to manifold like they did it in the 60's. Now I get 15* extra at low load all the time when the charge burns the slowest. As I get into the throttle the r's pick up and mechanical picks up and vac closes out when the charge burns the fastest. (Don't need all the advance)
Just saying it changed my truck for drivability.
Next I used the old 1.5 turns start position for idle mix adjustment. What I found was that I was always too lean even out some more. If you rev and drop you may hear pop. Too lean. Fatten up. Rev up and drop. Pipe rumble. Too lean. Fatten up. Trial and error and it will become very smooth from rev to drop off to idle. Now we are talking. Keep count of turns. (mine stopped at "5" turns). Shut down and set all the way back to a soft stop and recount each side carefully to the fat point. Very good idle, very smooth, runs cooler, better response from idle to take off. I get between 13 and 15 mpg regular.
Keep the idle under control. (hot idle and cold idle, if you don't understand get to work and get learnin. Set the choke correctly) I have a C6 and like my idle around 625 in park it goes to about 550 in gear. Prior to the tune above It would never drive around town at that idle without problems. Now I can Blatt Blatt Blatt around town real nice. Don't install too big of exhaust pipes as it will actually increase the backpressure on a stock engine. I have 2" or install a good 2 into one system, Prolly better performance.
Also the kick down, tune it up so it works right and I am adding a shift kit. These items make the sleepy smog engine more responsive. I got rid of the EGR after exhausting myself testing it. All I can say is crap!!!! Tapped the hole and installed a 3/8ths plug with inside allen to flush. Good riddance.
My 2 cents on a mostly stock smog mid seventies engine. 400 + cfm Ford 2v Carb and duals. A straight up time set may be better than a lift cam for low compression as it will maintain what dynamic compression you do have. The extra lift might really dog it out.
Lots of science left out but you can research all that. Otherwise cuss me! LOL

 

Hello again, im looking to do more to this old truck, what do you guys think I will gain for hp + tque if I add a set of the most basic hedman headers and also an edelbrock performer (not performer rpm) intake?


Thanks!

 

Early smogs sucked. Time set, the headers, mani and 600 cfm not sure how muchHP gain but your gonna like it. 2.25 pipes, low restriction muffs and dump at an angle in front of the back wheels. It will sound real nice.
All easy and fairly cheap.