Ive been thinking again....what would change if i swapped the cam to either a :

Comp Cams 255DEH

or a

Comp Cams 265DEH

Gains..losses...etc...

--John

 

255DEH
T = 468 ft-lbs@2000 RPM, 440 ft-lbs@3500 RPM
HP = 310@4000 RPM

265DEH
T = 446 ft-lbs22000 RPM, 449 ft-lbs@2500 RPM, 439 ft-lbs@3500 RPM
HP = 331@4000 RPM.

 

How about my setup now with roller rockers.....??

Any signifigant gains from switching to roller rockers?

Im thinking just the 1.73 ratio rockers, havent decided which brand to go with yet though...

Thanks

 

Roller Rockers will reduce frictional losses, and improve the reliability of the valve train. DD simulation does not have an option for type of rocker, so I can't tell you how much improvement you will see.

 

Probably in the neighborhood of 10-20 lb-ft improvement across the entire RPM range which translates into HP also. Some places suggest a bigger improvement but I have not seen any real good test data. Some of the manufacturers make claims and have shown some dyno charts on other engines but you know how some advertisers love to play with figures.

Pedestal mount rockers are available that do not require any machine work or guide plates etc that can run up the cost and add back in friction which can offset any gains. -TMI has the pedestal mount units. They can also be purchased from Ford.

 

Alright, so far with this motor and a 75HP shot of nitrous ive gotten my truck ( 79 F-250 4x4 ) to run a 14.32 in the 1/4 mile here in Denver..I think with a taller slick i can get it to maybe run a 14.15 or a 14.2. Id like to get a little more power on just the motor ( since i went from a best of 16.32 to a best of 14.32 with the little nitrous shot ). I finally got an actual race car, so my truck will only be raced 5 or so times a year....

Still havent switched cams, or intakes, but i did put on headers. Any suggestions on what would give me the best improvments? BTW, i have spun the middle out of 1 flexplate so far, before nitrous, and also busted a drum in my old transmission, again without nitrous.

I would really like to get rid of my edelbrock intake manifold, but really want to find a taller dual plane intake with more vertical intake runners...

I use Valvoline synthetic 5w30 in the winter, and Valvoline Synthetic 10w30 in the summer, and alswys add a can of BG MOA with every oil change, usually every 1750-2000 miles. I use BG Ultra Gard synthetic 75w140 in the rear diff, and use straight 90w valvoline GO with BG LS2 in my 203 t-case.... I saw a big increase in fuel mileage when i switched to the synthetic lube in the rear diff.