Another 273 for fun...

[Trauser]

I have a 1966 dodge dart GT all origional 273,904,7 1/4 it runs factory 4bbl manifold. I want to put the largest cam possible without changing heads,valves,springs you get the picture. Its for fun only. HELP ME OUT! don,t care about how bad gas prices want that nasty,nasty,lope.





I am building a 413 max wedge, 727,8 3/4. because ive always loved the 413.

 

[rumblefish360]

The OE valve springs are good for approx. .430 lift when fresh. Now that the engine is old, forgettaboutit. Get the springs new and matched with the cam, there only a few bucks more. This way, it doesn't become a waste of time and broken parts.

A chop to the idle is a narrow centerline, lower the number, more to the chop.

Typical muscle car sound is a 110 C-line.
Nasty chop is a 108.
At 106, it sounds like and acts like theres gonna be a stalling engine. Radical is the word.

 

[66fs]

Try Isky E-4 should be some sound clips here. Dont have any of mine yet. I agree with Rumlefish360 about the valve springs. I'd also add a double roller timing chain while I was in there. You should already have the solid cam valve train.

 

[Trauser]

Thankyou so much for the info. Cam brand suggestions?

 

[chewy]

The 35 year old HD Valve Springs that are on my original 273 heads were still holding close to 300 lbs at .450 lift. The only way to truly evaluate what you have is to either test them yourself, or have the machine shop go thru the head and test each one. In my case, no spring strength had been lost over the life of the engine. It really depends on the amount of lift as to the amount of spring you need.

I went with a Racer Brown ST-1 w/.450 lift cam. A little hotter than the high performance cam. 110 degree center line. 4 Degrees advanced built into the grind.

Its just my opinion, but I'm not going to replace the springs until I have a reason to. if I start getting valve float, then its time to change them for a stronger spring. Both the Machinist and the Cam manufacturer agreed with me on this point.

Breakin is in a few weeks when after I clean up under the hood.