So I swapped out the distributor springs for step up (replaced silver with copper) and the initial timing went from 6-7 to about 9-10...At 3000 RPM, total advance doesn't seem to be anywhere near 40 degrees. Mind you the highest markings are 12 degress, thus I am guessing the total...Sorry, I knwo I'm not making it easy...I have not change the timing short of the springs so....

 

Well, lacking good timing marks, I'm looking at the distributor instructions. The copper springs should be ok, I'd leave the timing like that and see what happens. I don't think that's going to fix your problems, though. Does it still backfire? How does it drive? Does it misfire, or does it just seem really slow?

 

Hasn't backfired since changing the springs and it never misfired. At this point, I think I'm back to where I was minus the lean condition...She just seems really slow and lacks the power I would expect with this setup...I agree that a bigger cam is in order as well as some heads, but I wouldn't think it would perform this bad, given the setup...

 

What year heads and what pistons are you using? How did you adjust the rocker arms? Might be to tight.

 

The Heads are stock cast iron (65 if I recall correctly). As part of the rebuild, I had them machined and new springs and seals added. The Machine shop said the valves were recent and didn't need replacing and that it appears to have recentlyundergonea 3 angle valve job. That said, they also said that it was probably the 3rd and last time the heads could handle a valve job and that new heads will eventually be the next step. Pistons are Speed Pro Hypereutectic (4.030). As for the rocker arm and lash adjustment, I found TDC on the #1 cylinder and in the correct order, simply spun the rod until resistance, then tightened them an addition 1/4 turn....

 

eep, that may be part of the problem. The proper adjustment is to zero lash + 1/2 to 3/4 turn. Zero lash is when there is no vertical play in the pushrod, not until you get resistance while spinning the rod. They may be adjusted waaay too tight. Go back and readjust them properly, then see how it works.

 

Look at the cam card and make sure you are using the correct timing order. There are two for the modern small block fords.

1-3-7-2-6-5-4-8 > 82 and later 302 HO firing order
1-5-4-2-6-3-7-8 > standard 289/302 firing order

If switched the engine will still run but sluggishly. Also you will have popping from the carburetor.
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Thanks everyone...I've double checked the firing order and it's consistant with the standard 289 order listed above...Just out of curiousity, I'm sure it "could" be possible that I was given the wrong cam and as such, what harm would it be to try the other firing order? In respect to valve lash, I've done it a few times by following the manual and in each case the Zero Lash was always attributed to rod spin....I want to make sure that I've got this part correctly, so can anyone summarize the best approach here? In the back of my mind I suspect my performance issue is timing or valve related as all parts have been specifically matched...

Remember, my last 0-60 time was about 13 seconds....Your thoughts?

 

Did you use any zinc additive in the oil during break in? Hopefully you didnt wipe out the cam.
http://www.cranecams.com/pdf/548e.pdf

 

Yep, used the CompCams Zinc additive. Followed the break in proceedure to a tee...