Need help with 408 Build

-
dwire67

dwire67

Well-Known Member
Joined
Nov 12, 2009
Messages
976
Reaction score
42
Location
Seaford, Delaware
I am in process in putting Duster from a Drag Car , back to a street car.
Here is the way I am going -Hotckis rear springs, sway bar, rear disc brakes, front disc brakes Magnum force upper control arms with Heim ends, Feel Firm tie rod sleves , front sway bar , 920 torsion bars, flamming river steering box
8 3/4 with 3.23 489 case with eaton tru trac, Passon 4 speed
Tires 275 50 17 rear 245 50 17 front. I want this to be a driver so I was going with a 408 -Edelbroc heads, Icon pistons IC745, Scat crank, Compstar H beam rods, LD4 340 intake, now when it comes to a cam that is where I don't know what way to go? do I go solid roller? Hydraulic RetroRoller? and also as far a Carb put a Thermo quad on it? or Holley? I have a 850 holley and 950 ? Or do I just put the one engine a 360 that I had in the car for while and it went 12.00 with DOT tires and mufflers:burnout:
 
With what you have I think the cam should be in the 245-250° @ .050, if it was me, I'duse a solid flat tappet. No need to spend on the rollers unless you feel uncomfortable with break in and running decent oils. I'm no fan or the retro kits. If you want to run a roller, use a Magnum or roller LA block and run one. It's the cheapest way to get it.
The intake is dated. If there was a blank page I'd suggest the RPM. If not, not a huge deal but that intake does give up power.
On the carb, the best all around carb I've found is the Street Avenger 870 VS. The 950 would be my second choice, I think the 850 is a little small but it will work also. The Thermoquad should not be used IMO.
 
No problem here with a solid flat tappet , that is all I have ever run. I thought the LD340 would help with bottom end power. I have a M1 ,Victor 340 , holley strip dominator and a Toker 2 also.
 
With a 4" stroke, you will not have an issue with response or low end torque. These things are like a 440 on steroids. They have 1/4" more stroke than a 440, with 20% less weight..lol. I think the best of what you have would be the M1 single plane. Port match the heads to it, and make sure you have the heads checked and corrected. Gasket match the exh ports.
 
I thought the LD340 would help with bottom end power.
Click to expand...

Completely agree with Moper (not that he cares LOL!)

The old "Single Plane for a Revver" rule went out the window with the 4" small block "arm".

I went from an LD340 to an M1 with the same 800cfm carb - made 17 RW HP more, and the thing will still light the tyres up if i sneeze on it.

An Air Gap might be a little better than an M1 SP for mid range torque...but thats about the only DP thats worth using in these things....the older intake plenum sizes and runners are just too small to feed them properly high up.

If' you;re planning to tow the Earth out of orbit...then use the LD340.
 
You must log in or register to reply here.
-

Back
Top