Originally Posted by Andy316

I ran same setup as you. shaved heads and all. At the same track as you, and i can tell you, your top end is non existant. I see you say you need to tune your carb. Do that. Open up the exhaust. I had 2.5" off of dougs headers either open or through and x pipe. Should be trapping around 103-105 with that combo and gear i would say. What rpm are you shifting at also? Good luck, its a solid combo.

Originally Posted by M1tch

thanks for breaking it down for me, will those rockers fit onto my vortecs?

Originally Posted by bluegrassz

Most stock center bolt valve covers require narrow body roller rockers. I modified my covers to use the Crane Gold regular body.

You can check with Summit Racing and see if they have a set of there brand that will fit.

Originally Posted by 1qk4mula

If u change the gear set without a set of slicks.. u are probably going to run slower..

U already said u are spinning, the gears are only going to make matters worse.

I have 2.73 gears no posi in my drag car. It works good for me. I run high 10s with stock LT1 and 150 shot. The car goes straight, no wheel spin or funny business.

Originally Posted by Shaun4BigBlocks

I would say that it would depend on how your heads are setup. Overall the Vortecs are lower reving torqy heads so leaving the hole isn't as important as making up for the RPM loss, especially in a light uni-body car. In that case I would say 342's are perfect, 273 gears suck with the exception of gas mileage, umless of coarse you cruise under an ideal cruising RPM. If you have 2.02 valves and the springs set up for a high .500's cam I would consider the 373's, but remember that the gears would ideally be compimented with a higher then stock stall speed to level out the power curve. A general rule of thumb is to stick with 2'1/4 for 250-300 HP and 2/1/2 for 300-350 HP. Yes, your 2" is probably killing you, unless if you are still running the stock Vortec roller. The mandrell bent pipes are definately ideal but not as big of a factor as having the right size. If you get to large a size you will hurt your back pressure and loose some precious oompf off of the line. Remember also that the size depends on if you are running true dual or a single cat back system. True dual 2" will run like 2 1/4 cat back since you get the increase in flow. There are still many other factors such as are you carbed or FI? Do you need to rely on a computer friendly duration or can you get away with a single pattern cam? Hope this helps. Blocks-

Originally Posted by bluegrassz

So you really dont know were your timing is at. That being said, you are leaving some hp on the table.

Have you tried a piston stop and remark your balancer? If its a 6 3/4 balancer, you can get a timing tape or cover that is marked. On the stock tab, for every ^ the point is 2* and every valley is 2* if I remember correctly starting at the deepest valley. The notch on the balancer should be lined up with the deepest valley on the tab at TDC.

Stock base timing for a TPI motor is 6*. With your setup you should start with a base of 10*-12* and aim for 32*-34* total all in by 3k. This will get you in a ballpark.

Originally Posted by M1tch

Another thing i'm concerned about is the secondaries. How much are they supposed to open? on my 650 if they open past 45 degrees it clicks and opens to about 80 degrees. i havent had somebody check it but i might not actually be getting full throttle the way my pedal is set up

Originally Posted by M1tch

My throttle bracket was loose. My secondaries were only opening about 25-30 degrees. I pulled it back and took it for a drive and i felt a world of difference! Haha

Originally Posted by M1tch

My throttle bracket was loose. My secondaries were only opening about 25-30 degrees. I pulled it back and took it for a drive and i felt a world of difference! Haha

Originally Posted by z28freak84

Are u serious?! Your only problem was the throttle not opening?!

Originally Posted by M1tch

Hey guys I have a few updates..

I took my car to a performance shop and they changed my spark plugs to the right ones, from .460 reach to the standard vortec .708. They also found TDC on my balancer and had to move my distributor around to get it right. They said its advancing now up to 25 degrees and running a heck of alot better than it was. They said it idles better and has better response than before. They're now going to get the additional timing around 34 degrees but they said my vaccum advance can isnt working. But I thought it only works under part throttle? They said holleys port on the carb still draws vaccum under full throttle which will help my timing go from the 25-34-36 degrees. Any truth to this?? They run some badass cars at the track and they have been very legit so far

Originally Posted by M1tch

Yea they said there was plenty of room, they said i could run 1.6s if i wanted to

Originally Posted by M1tch

They also found TDC on my balancer and had to move my distributor around to get it right. They said its advancing now up to 25 degrees and running a heck of alot better than it was. They said it idles better and has better response than before. They're now going to get the additional timing around 34 degrees but they said my vaccum advance can isnt working. But I thought it only works under part throttle? They said holleys port on the carb still draws vaccum under full throttle which will help my timing go from the 25-34-36 degrees. Any truth to this?? They run some badass cars at the track and they have been very legit so far

Originally Posted by brandoz28

i've got a set of 1.6 cranes pm me if interested. glad to hear its getting sorted out though. wanna hear how this thing runs at the track

Originally Posted by five7kid

Holley's have both "full manifold" and "timed" vacuum ports, so it depends on which one you use. I prefer full vacuum for non-emissions applications, tends to improve idle.

Originally Posted by five7kid

Holley's have both "full manifold" and "timed" vacuum ports, so it depends on which one you use. I prefer full vacuum for non-emissions applications, tends to improve idle.