[toomanymodz]

Here I will post my combo and how well it performs in the 1/4 mile, along with the changes I've made and what it did to the performance. Enjoy.

Combo:
1966 Chevelle Malibu 3350 lbs
Engine: .040 over 400 Small Block with .125 extra stroke = 423 CID 10.7 to 1 compression.
Brodix Dragon Slayer heads 225cc
Jones custom hydraulic roller 240/243 duration. .600 lift (1.6 rocker) on a 110 spread.
Performer RPM intake manifold with 1 inch spacer
Pro Systems 840 carb
1 5/8 Hooker comp headers
Pypes 2 1/2 inch exhaust
Original 10 bolt rear with 3.08 posi
TH350 with Turbo Action 2800 stall
275/60 nittos

2nd pass on brand new combo:
11.88 ET @ 113.9 MPH. 1.75 sixty foot

I took at back to the track a month later, no changes, just increased shift-point to 6800:
11.89 ET @ 116.11 MPH. 1.84 sixty foot

Decided to swap out the 1 5/8 headers for 1 3/4 Super Comp. mainly because of fitment issues with the spark plugs.
11.77 ET @ 115.71 MPH. 1.74 sixty foot.

Changed to AFR 220 heads. Installed a Moser 12 bolt with 3.73 gears. Converted the power steering to manual. Changed to Pypes 3 inch exhaust. Installed Mickey 295/55's.
11.63 ET @ 115.98 MPH. 1.65 sixty foot.

So as you can see, a ton of $$ spent and hardly no performance gains. I even swapped out the Performer RPM for a Holley Strip Dominator with no gains (just lost a ton of throttle response on the street).

I guess the lesson I learned here is when a combo works right the first time, don't monkey around with it.

 

[Aml383]

Here I will post my combo and how well it performs in the 1/4 mile, along with the changes I've made and what it did to the performance. Enjoy.

Combo:
1966 Chevelle Malibu 3350 lbs
Engine: .040 over 400 Small Block with .125 extra stroke = 423 CID 10.7 to 1 compression.
Brodix Dragon Slayer heads 225cc
Jones custom hydraulic roller 240/243 duration. .600 lift (1.6 rocker) on a 110 spread.
Performer RPM intake manifold with 1 inch spacer
Pro Systems 840 carb
1 5/8 Hooker comp headers
Pypes 2 1/2 inch exhaust
Original 10 bolt rear with 3.08 posi
TH350 with Turbo Action 2800 stall
275/60 nittos

2nd pass on brand new combo:
11.88 ET @ 113.9 MPH. 1.75 sixty foot

I took at back to the track a month later, no changes, just increased shift-point to 6800:
11.89 ET @ 116.11 MPH. 1.84 sixty foot

Decided to swap out the 1 5/8 headers for 1 3/4 Super Comp. mainly because of fitment issues with the spark plugs.
11.77 ET @ 115.71 MPH. 1.74 sixty foot.

Changed to AFR 220 heads. Installed a Moser 12 bolt with 3.73 gears. Converted the power steering to manual. Changed to Pypes 3 inch exhaust. Installed Mickey 295/55's.
11.63 ET @ 115.98 MPH. 1.65 sixty foot.

So as you can see, a ton of $$ spent and hardly no performance gains. I even swapped out the Performer RPM for a Holley Strip Dominator with no gains (just lost a ton of throttle response on the street).

I guess the lesson I learned here is when a combo works right the first time, don't monkey around with it.

Wow yeah that's very close to a dead ringer to what I've got going on ..still putting motor together.
Same car and tranny with many likenesses to engine and drive train
What rpm are you passing the stripe at ?
What cam are you running?

 

[Aaron]

Any goals? People can start arguments over threads like this. Im not interested in any of that. If I see some goals, I can then relate my experiences to what your combo.

 

[77 cruiser]

You want to spend more try 3.73 gears & about a 4000 stall conv.

 

[toomanymodz]

With the 3.73 gears I'm crossing the stripe at about 5500, which isn't ideal. When I ran the 3.08's, I could stay in 2nd gear and cross at 6800. This is probably why the 3.73's really didn't help much. My ultimate goal wasn't ET, but more focused on MPH. 120 was my goal but it is way out of reach at this point. Whatever I throw at this, the MPH stays the same. The only worthwhile mod in all of this was the Mickey Thompson tires.

 

[77 cruiser]

I missed the gear change. MPH is a function of HP.

 

[Aaron]

Heading says street combo. I will ask questions. How do you drive? How often you drive? How you far you drive. Commute or weekend car?

 

[Aml383]

If you want better ET and mph and you have the money a GV unit is an option .
Many on here say they are too big an expense and many others say they are worth every nickel.
Worth every nickel ofcourse is a relative phrase . Relative to the depth of your pockets and the size of your balls lol
Those units sort of let you have your cake and eat it too. With frosting.
If you arent familiar with them they bolt behind the automatic tranny and turns your 3 speed 350 into 6 speeds with ratios cut in half.
So for instance...you said you are finishing a quarter with a 373 gear in hi tranny gear (1:1)@ 5500.
With the GV unit you can still shift twice like you are now but instead of finishing at 5500 rpm in a high 1:1 gear ... you finish the quarter at maybe 800 to 1000 rpm higher because you finish with a 1.19:1 tranny gear.

Not only that if it works better with your combo you can shift 3 times instead of 2 to get to that same 1.19:1 gear.

AND you've got a NICE overdrive .
Gv unit gives you
1
1H
2
2H
3
3H
at very close ratios .
Its 3 grand man but it is worth every nickel to me . I'm gettin it

 

[Geo71]

Don’t feel bad. I went from 3:31 to 3:90 with no difference in et. It just let me get into drive.

With your combo, I would go to a single plane. My old 388 ran similar times and mph. More compression and a solid roller but much smaller heads.

Or be happy with it, 11’s are plenty peppy on the street or track.

 

[jeff swisher]

Are you running a stock drive shaft?
Little 2.5" diameter unit.
I could not get my engine to rev in high gear well with the stock shaft. 6000 rpm was it.
I see you are way below that but those tiny diameter things harmonic and begin twisting up early in the RPM.

I would have expected much more MPH from that combo.

Your profile states Florida so You are probably not fighting 4000 ft altitude.

This Nova I built for a buddy is about the same MPH as yours little 357" and 305 heads 292H cam
Most of the time it ran 115 MPH and only 1 time it hit 117.
I felt he needed to shift earlier than 7400 but he just would not try it.
3300lb with driver.

1978 Chevrolet Nova 2dr 1/4 Mile Drag Racing

1978 Chevrolet Nova 2dr runs 11.940 @ 115.000 in the 1/4 mile

www.dragtimes.com

I feel something is holding that thing back.
I assume you checked to make sure the carb is opening all the way.
I assume you tried a lot less timing and more timing.

 

[pockets]

What total timing have you tried? Have you had someone sit in the car, floor the gas pedal and you confirm it actually goes full throttle? Have you taken the carb off and confirmed that the blades actually go full throttle (90 degrees to the throttle bore)? What is your fuel system set up?

 

[Aml383]

Are you running a stock drive shaft?
Little 2.5" diameter unit.
I could not get my engine to rev in high gear well with the stock shaft. 6000 rpm was it.
I see you are way below that but those tiny diameter things harmonic and begin twisting up early in the RPM.

I would have expected much more MPH from that combo.

Your profile states Florida so You are probably not fighting 4000 ft altitude.

This Nova I built for a buddy is about the same MPH as yours little 357" and 305 heads 292H cam
Most of the time it ran 115 MPH and only 1 time it hit 117.
I felt he needed to shift earlier than 7400 but he just would not try it.
3300lb with driver.

1978 Chevrolet Nova 2dr 1/4 Mile Drag Racing

1978 Chevrolet Nova 2dr runs 11.940 @ 115.000 in the 1/4 mile

www.dragtimes.com

I feel something is holding that thing back.
I assume you checked to make sure the carb is opening all the way.
I assume you tried a lot less timing and more timing.

Seems like the gearing is the problem and I think the head is too big . 220cc

Car only gained a little over .1 et going from 308 to 373 gear and that gain was in the 60 foot time BUT the car finished in second gear with the 308 @6800 at max hp and it finished with the 373 gear @5500 at max hp - probably 70 hp
There is the difference.

If the transmission and rear dif gearing were set up so that the car is ET @ 6800 or 7 grand in hi gear with the 373 gear it still gains the .1 in the 60 feet plus whatever gain it would get from 5500 rpm all the way to nearly 7 grand.

Gearing in the car is not optimal for a drag race .

Solution to optimize ET :
either put 430 gears and a big stall and the right suspension to get all that to hook = 3 grand plus minus
OR leave the 373 or even a 355 street friendly gear in it and spend the 3 grand on the GV unit .
Thats my story lol
Also (and I'll probably take some shit for this) I'd tighten the LSA to 108 absolute max. Maybe 106 or 107 along with a smaller intake runner . 200 or 210

 

[bracketchev1221]

I would put the motor on the dyno to see if it is the motor down on power or the car holding it back.

 

[toomanymodz]

I mainly drive it around town. I go to the track maybe once a year. A 2 hour drive each direction and I cruise at 65 mph at 3k. The car gets really good gas mileage so no complaints there. I run 35 degrees total timing. More timing doesn't net anything. The throttle blades have been verified as being 'wide open' when the pedal is mashed. I have an AFR gauge and it reads around 12.8. I've experimented with a richer mixture as well as lean with minimal gains. The 210cc heads probably were a better choice but I must run what I have. The car has an aluminum driveshaft with billet yoke.

I could go with a 10 inch converter, maybe around 3500 stall and get even better sixty foot times, but I'm actually happy with the 11.60 ET. Achieving my goal of 120 MPH means that I have to find another 40+ HP somewhere, or spend the $$ on a Gear Vendors unit. I don't know if they fit our floor pans without cutting. And my exhaust crosses under the driveshaft and I probably would have to change that as well.

I took it to a chassis dyno last year. It was the type that bolts directly to the axle studs. The results were very optimistic, to the point where I don't believe it. It made 500 HP at 6500 RPM and 482 TQ at 4000 RPM. My hillbilly calculations say that it's really making closer to around 450 HP to the wheels.

 

[77 cruiser]

3350 is that with you in it?

 

[toomanymodz]

3350 is that with you in it?

No, it would be 3550 lbs with me and tools.

 

[pockets]

What mufflers? Are they chambered or straight through? What oil pan, and does your oil pressure fluctuate with rpm? I think you need more exhaust duration on the cam. 1 7/8" headers would also be better for that cubic inch/stroke.

I would also consider sending the intake to Wilson to be ported.

Have a look here at suggestions listed for with this cam spec'd for your heads/bore/stroke.

HR-9602-8-CSR SBC 400 to 427 CID AFR 220-235 Head Max power 6300 rpm Peak torque 3500

Clay Smith Cams, home of Mr. Horsepower engineers world class camshafts and custom cams. If you need extra horsepower, performance and the muscle car sound, check out our line of cams.

www.claysmithcams.com

 

[Aml383]

I mainly drive it around town. I go to the track maybe once a year. A 2 hour drive each direction and I cruise at 65 mph at 3k. The car gets really good gas mileage so no complaints there. I run 35 degrees total timing. More timing doesn't net anything. The throttle blades have been verified as being 'wide open' when the pedal is mashed. I have an AFR gauge and it reads around 12.8. I've experimented with a richer mixture as well as lean with minimal gains. The 210cc heads probably were a better choice but I must run what I have. The car has an aluminum driveshaft with billet yoke.

I could go with a 10 inch converter, maybe around 3500 stall and get even better sixty foot times, but I'm actually happy with the 11.60 ET. Achieving my goal of 120 MPH means that I have to find another 40+ HP somewhere, or spend the $$ on a Gear Vendors unit. I don't know if they fit our floor pans without cutting. And my exhaust crosses under the driveshaft and I probably would have to change that as well.

I took it to a chassis dyno last year. It was the type that bolts directly to the axle studs. The results were very optimistic, to the point where I don't believe it. It made 500 HP at 6500 RPM and 482 TQ at 4000 RPM. My hillbilly calculations say that it's really making closer to around 450 HP to the wheels.

Man if your takin the car to the track once a year and you like the 11.60 ET and the car cruises 65 at 3 grand your good brother!!
Lol. Leave it alone. 11.60 is a FAST car man lol. For the street for sure it is .
Swap a cam, change an intake and or port an intake, maybe play with carb or try another one ...aside from that I'd say you got your girl right there lol. She behaves well in public but is perfectly ok lettin you give it to er Hahaha
PERFECT

 

[68Chevele]

Here I will post my combo and how well it performs in the 1/4 mile, along with the changes I've made and what it did to the performance. Enjoy.

Combo:
1966 Chevelle Malibu 3350 lbs
Engine: .040 over 400 Small Block with .125 extra stroke = 423 CID 10.7 to 1 compression.
Brodix Dragon Slayer heads 225cc
Jones custom hydraulic roller 240/243 duration. .600 lift (1.6 rocker) on a 110 spread.
Performer RPM intake manifold with 1 inch spacer
Pro Systems 840 carb
1 5/8 Hooker comp headers
Pypes 2 1/2 inch exhaust
Original 10 bolt rear with 3.08 posi
TH350 with Turbo Action 2800 stall
275/60 nittos

2nd pass on brand new combo:
11.88 ET @ 113.9 MPH. 1.75 sixty foot

I took at back to the track a month later, no changes, just increased shift-point to 6800:
11.89 ET @ 116.11 MPH. 1.84 sixty foot

Decided to swap out the 1 5/8 headers for 1 3/4 Super Comp. mainly because of fitment issues with the spark plugs.
11.77 ET @ 115.71 MPH. 1.74 sixty foot.

Changed to AFR 220 heads. Installed a Moser 12 bolt with 3.73 gears. Converted the power steering to manual. Changed to Pypes 3 inch exhaust. Installed Mickey 295/55's.
11.63 ET @ 115.98 MPH. 1.65 sixty foot.

So as you can see, a ton of $$ spent and hardly no performance gains. I even swapped out the Performer RPM for a Holley Strip Dominator with no gains (just lost a ton of throttle response on the street).

I guess the lesson I learned here is when a combo works right the first time, don't monkey around with it.

Change the convert to something in the 4500 stall range, that should help. PM me and I will give you the run down on my 406 Combo that hit the high 10's with Vortec heads.

 

[GTO44]

You’d get a nice bump in power if you went to a 1&7/8 header setup or bigger. You’re effectively choking the motor with the 1&5/8.

I dont agree with “those heads are too big”. Richard Holdner has proven time and time again that’s not a thing. But with a motor being nothing more than an air pump, you need to be able to get the air out when you’re taking that amount of air in.