Is this a good 318 combo for my 70 dart???

[shawndao]

Is this a good combo for my 70 dart? have everything for the 318 except the convertor...just want some opinions from all the knowledge floating around on this site..doing a budget build, so this is what I have..thanks


1969 318---in 70 dart
edelbrock dual plane intake
holley 600 carb
thumper cam (specs below)
long tube headers
2500 stall/904 auto--only have stock convertor for now. (if anyone has one for sale please let me know)
8.25 posi rear (3:14)


cam specs
Cam Style:Hydraulic flat tappet

Basic Operating RPM Range:2,000-5,800

Intake Duration at 050 inch Lift:227

Exhaust Duration at 050 inch Lift:241

Duration at 050 inch Lift:227 int./241 exh.

Advertised Intake Duration:279

Advertised Exhaust Duration:296

Advertised Duration:279 int./296 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.486 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.473 in.

Valve Lift with Factory Rocker Arm Ratio:0.486 int./0.473 exh.

Lobe Separation (degrees):107

grind Number:279TH7 Lifter Style:Hydraulic flat tappet


outside Diameter of Outer Spring (in):1.437 in.

 

[C130 Chief]

With stock heads and compression ratio, that's a lot of cam. It'll sound mean you're after, but you'll probably go faster with something a bit milder.

 

[shawndao]

What heads would be better for this combo? (remember budget build) haha

 

[bad440]

A set of 302 castimgs would be what you want

 

[DaveBonds]

Keith Black pistons would be nice, but if you don't want the bottom end apart, the ...302 cast number heads will bump compression. Be sure to mill them .010" or less to square them up for some Mr Gasket 1121G .028" compressed thickness gaskets. http://www.summitracing.com/parts/mrg-1121g?seid=srese1&gclid=CNzrmZejw70CFUVgMgod8DoAOg

I still think that cam is too top end (RPM range) for any stock bottom end. I'd go with something in the 470-490 lift range and a good lobe separation angle. Keep the overlap down. Doesn't sound as cool, but if you want torque, you need vacuum or a lot more compression.

 

[Coronet 500]

The 302's will give a slight increase in compression but a much better port.

The Comp Cam XE 268 H will make 12 more HP and 26 more TQ than the Thumpr.

 

[shawndao]

Thanks for all the input!