[chevytrucknut]

Hello, We have a 350 in a 71 chevy truck. It had an upgrade HEI from points, with a edelbrock intake and carb. Was running fine until we decided to upgrade the cam. Installed a Automotive Alliance camshaft, lift .489in .487ex duration of 324*in 318*ex. At @.050 duration is 275*in and 274*ex with overlap of 95*. Well my problem is we got it started but really rough. Put on a timing light and unable to see the timing mark. The rotor is pointing at #1, the plug cable are one position counterclock wise this is where we were able to get it started. What did we do or go wrong?
Thanks for your help.

[johnsongrass1]

I think you need to recheck the .050 numbers.


SEt timing by loosening the dist lockdown and starting the car. Then shoot the light at the crank and turn the dist till your marks line where they are suppossed to be. Lock down the dist. and call it good.

[techinspector1]

You guys have made the same mistake that thousands of others have made over the years, assuming that a humongous cam will make humongous power in an otherwise mostly stock motor. Nothing could be further from the truth.

The cam you've chosen needs at least 12.5:1 static compression ratio to operate properly and will make power from 5,000 to 8,500 rpm's. I hardly think that's what you had in mind when you set out to improve the motor.

Yank that cam and replace it with something like this....
http://www.cranecams.com/?show=brows...tType=camshaft
This cam will work well with a relatively stock motor, OEM cast iron heads and stock converter.

[docvette]

Doc here,

You Did pull and plug the Vacuum advance (If used) before timing right? That will over shoot the timing marks if left hooked up..

Just checking..

Doc