Jim, It sounds to me as though you are a Mudfooter-hence-you should probably
build for the widest torque band possible. All the ideas you suggested are
more geared towards high rpm/non emissions applications. Plus they add up to
well over $5000 in parts. So dollar for dollar, that motor combo still won't
have a flatter torque band tha a 360 will net you. Stroking a motor is very
spendy, 1500-2400 bucks for the crank-then pistons-then rods accompanied by
machine work and time, whew, lotsa cool stuff but real spendy. You probably
want to puke torque from idle in a 4x4. If you build for the widest torque
band, the horsepower will fall into place. I went to a junkyard and found 3
or 4 360 magnums for $1200 to $1000 with wiring harnesses. One was very low
milage. As for Extrude Honing, doing all 3 parts is advantageous (extrude
honing loses no torque compared to the average street ports due to the
velocity staying up) but the bad point is, $600.00 for the intake, $500 for
the exhaust and $980 for the heads. Have a machine shop do some mild bowl
work and smooth the short side radius for $200 to 250, don't open up the
intake or exhaust runners, but polish the exhaust runners withoout altering
its shape. Stick with the exhaust manifolds and air dremel the runners as
smooth as possible and open up runner #8 by removing 1/16 of the material
wall. Here's my recipe for a 360 that will put out well over 400 ft lbs of
torque from idle to 4000rpm:
1. 93 up 360 with wiring harness
2. Mopar 112 cam or Crane 2020 (112) camshaft, stock springs
3. Port and polish the exhaust manifolds
4. Port and polish the TB-(though not necessary for naturally aspirated/low
rpm applications)
5. Balance the piston and crank assembly within 1/2 gram
6. Single 3" cat and 3" catback exhaust
7. 320 bucks for the Crane roller rocker assembly
8. Head work mentioned earlier
9. Timing set that has 3 keyways, advance the cam 4 deg to move the powerband
down
10. Usual K&N filter and MP computer with an MSD or Crane MFG boosting the
coil.
This adds up to $2000 to 2500 bucks ready to roll. If money permitted,
adding a supercharger with 5 to 6 psi will get well close to 500 lbs torque
(can -u-say bye, bye tranny?), but we are budget minded so the point is,
build your motor for the most power at low rpm's so that it never has to go
over 5200 rpm! (torque and horsepower band always cross at that rpm) Then
stick with the stock stall converter because the more torque you make, the
higher stall you'll get from a converter. Add a shift kit and 3.70 to
3.90ish rear gears. Your wallet will love you and so will the local tire
store. :-)
KUK
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:50 EDT