Best gear ratio

[69 GTX]

3:54 big block, 3:73 small block.

 

[RT K_line]

I was recommended a cam with a .509 lift with 292 duration could I get similar times with a cam like that

That's a good cam with at least 10 to 1 compression motor. I built mine to six pack specs. I was running the purple shaft solid 296 557 and the car was actually faster. 12.30s

 

[RT K_line]

These guys are all nuttier than squirrel turds. 4.10's is all ya need.

Yes I'm thinking about 4.10s but I haven't sprayed my combo yet and don't want to put in a roll bar. I had 4.10s in my 70
GTX and think it is actually the perfect gear. Before I raced on the streets but I won't do that anymore so 4.10s is right at the limit to drive to the track.

 

[Chris1973Rr]

That's a good cam with at least 10 to 1 compression motor. I built mine to six pack specs. I was running the purple shaft solid 296 557 and the car was actually faster. 12.30s

So if I run the same gears and stall as you and my engine wouldn't be built the same as yours but if I run the .509 cam you think I could at least get high 12s low 13s

 

[dieseldazzle]

Yes I'm thinking about 4.10s but I haven't sprayed my combo yet and don't want to put in a roll bar. I had 4.10s in my 70
GTX and think it is actually the perfect gear. Before I raced on the streets but I won't do that anymore so 4.10s is right at the limit to drive to the track.

My 4.10 :

1.68 60ft on motor
1.57 60ft on spray 215 shot

3.55
Never bothered to run it on motor after moving to nitrous. Matter of fact I don't think I've had anything with a 4 barrel carburetor on it since 99 that hasn't had nitrous on it, since moving to nitrous.

1.48 60 ft on nitrous

All combos are different and I had went to a 3.55 gear because A. I drive it across country from Alabama to California and B. I was going through the traps off the 6250 limiter on the motor with 4.10s

It did the same thing with 3.55 and spray tho.

 

[RT K_line]

So if I run the same gears and stall as you and my engine wouldn't be built the same as yours but if I run the .509 cam you think I could at least get high 12s low 13s

It's hard to say but if you check out the 12 second section in the racers section you will find a few cars with that cam and some give their combo's. That may help you with yours.

 

[Chris1973Rr]

It's hard to say but if you check out the 12 second section in the racers section you will find a few cars with that cam and some give their combo's. That may help you with yours.

Thanks for the info

 

[66Satellite47]

Making a 383 go well into the 12's can be done. Stock iron heads need a fair amount of pocket porting which gets really good results. Camshaft choice is really tough. I got a really good solid cam with the first drag car I bought. After that I tried a mushroom lifter .635/645 (very antique but really works), 720 276 Comp roller way slower than the mushroom, Comp re-ground the 720 to 660 280 which was about the same as the mushroom, then a 690 284 Lunati, a little more power than the 660 & the mushroom cams. All these were for bracket motors I was running. The 660 & 690 rollers were hard on valve springs. I'm sure today's springs are much better. My new 512 motor has a Comp solid custom under 600 both int & exh with 260 - 270 @ .050. You get a very different cam when the experienced engine builder is talking to the "back room techs" to get the cam profile recommendation. To the point, cam selection for what you are going to do. My impression is that new designs are much better than the old stuff, could be wrong (my antique mushroom is an example).