390 Compression Test & Crankshaft Question

[TEL73]

The car drives good. It's not a problem to get on the hwy and run 70. The acceleration is the issue. The best way I can describe it is like a 2 barrel with the timing set too low.

[machoneman]

But, have you checked the timing chain yet?

[TEL73]

No, factory correct fuel pump will be here tomorrow.  I'm going to check it when I swap those out. I'll give an update on my findings.

[chris401]

Yes chain. Also check accelerator pump on carb. Getting two good streams under the choke? I have always seen a bad pump leak. It may be possible the weep hole is plugged. If you have a Holley make sure cam and linkage are in place and traveling when you open the throttle. If so check a for plugged squirter. Holley has one screw to hold squirter in place.

[ScotiaFE]

At 120 psi and 30% leakage sounds like you have a old 390 truck engine.
Which is a low compression work horse with puny cam.
That combined with your 3.00 rear gear and 4500lbs will always just lumber along.
The question is how much giddy up do you want?
That is directly proportional to the amount of money you are willing to spend. 
The best way and most cost effective to increase giddy up is to change the rear gear.
3.50 is the best all around for street and highway. This is of course just my wag, others may have a different wag.

[KMcCullah]

It sounds like it has some miles on the rebuild but it's got some life left in it if the exhaust valves aren't sunk. I'd start with a good tune up an go from there.  A 65 T-bird is a heavy car with long legged gears. When it was new and fresh, that 390 might have made 300hp...maybe. And right out of the box I doubt it would bark the balonies. Changing the rear dif gearing would be the best bang for the buck after a tune-up. But like we all say.....life is better with a stroker.   

[TEL73]

Update on the findings. The timing chain looks good. I have noticed a slight miss. Not a dead miss. It's especially noticeable around the 1500 rpm range. I haven't found any exact numbers but one website said the 0-60 time on a 65 tbird was just under 11sec. Checked mine over the weekend and it's best is a 12.88 just to give you an idea of what I mean by low power.

[Heo]

Is the distributor advancing
The ignition timing corectly?
The wheights in dist can
Get stuck