I recently purchased a 76' TA with a 455. I have no idea what was done to the engine. I know some work has been done because it has headers, true dual exhaust with equalizing pipe and an edelbrock intake. It has the original quadrajet and distributor. I ran it at the strip last week and pulled a miserable 15.3 at 89 MPH. The engine would go much past 4500RPM. It ran good, but just ran slow!

I also have a problem with the timing. I have to advance it to apprx. 16-18 degrees below top dead center to get any kind of power out of the motor. Of course, with that much advance, I can't start the car when the engine is hot.

Does anyone have any ideas of why the timing has to be so far advanced, or is this normal for the 455. I'd also liketo know if the time sounds normal for the 1/4 mile. I would have thought it should be atleast around the low 14's.

Any input would be appreciated.

 

First off, I'd like to appologize if there's a time limit between the first post and reply. I guess this is the only way to find out...

As for your '76. A very nice purchase. Be nice, as only 7,099 or so ever saw the light of day!

I'd say the first weak spot on your quest for performance is the Q-Jet. Most people disregard them as economy mixers because of their complexity. But they can serve wellin mild performance settings. The first thing you should do is pop the plugs off the mixing screws in the back, as they were set at the factory for fuel economy in order to satisfy GM's CAFE. You can now run richer or leaner to gain what performance you can out of it. Of course, with some research, you can pull more out of your carb so that it can exist for better reasons than supporting the shaker (If so equipped).

Next I'd change the weights in the distributor. Simple, and self-explanatory when you pop off the cap and rotor.

But bottom line is anything higher than 4500 for long periods and you may see the downfall of Poncho big blocks. They don't spin well at higher RPMs.

Hope this helps out...

 

Might want to check for play in the timing chain. How many miles are on the engine? Does it look like the heads were off? Dave K.

 

take it to your favorite mechanic!