Hi Guys,

I've noticed that when I get back from a drive (engine hot), pull my car into the garage and get out, there is a heavy gas smell near the back of the car. There is enough (unburned) fuel in the air to burn my eyes.

When I was looking closer at the exhaust pipes for richness, I noticed some residue (gas) on the bumper.. Almost looks like little drops.

427
Aluminum Heads
GM 163 Intake - high rise - dual plane
Big Mutha Thumper Cam
10:1

Running a Holley 4150 - 750 DP, Mechanical. The previous owner didn't think it was enough carb so he was changing power valves and such.

I used Holley's 'selector (http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp)' and it indicated that an 850 vacuum would be a better fit.

http://www.holley.com/applications/CarburetorSelector/0-80531

I prefer a bit more driveability (if you can really call it that with the BMT cam).

Thoughts?

Thanks in advance

Hi Guys,

I've noticed that when I get back from a drive (engine hot), pull my car into the garage and get out, there is a heavy gas smell near the back of the car. There is enough (unburned) fuel in the air to burn my eyes.

When I was looking closer at the exhaust pipes for richness, I noticed some residue (gas) on the bumper.. Almost looks like little drops.

427
Aluminum Heads
GM 163 Intake - high rise - dual plane
Big Mutha Thumper Cam
10:1

Running a Holley 4150 - 750 DP, Mechanical. The previous owner didn't think it was enough carb so he was changing power valves and such.

I used Holley's 'selector (http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp)' and it indicated that an 850 vacuum would be a better fit.

http://www.holley.com/applications/CarburetorSelector/0-80531

I prefer a bit more driveability (if you can really call it that with the BMT cam).

Thoughts?

Thanks in advance

The previous owner screwed up in seconds what Holley engineers spent countless hours perfecting.Grab yourself a Holley manual and return the 750 dp to factory settings.Nothing wrong with a vac secondary 850 over 427 cid..the engine dictates secondary flow so it is hard to overcarberate,but the 750 dp set up correctly should not be a problem with this CID.

The previous owner screwed up in seconds what Holley engineers spent countless hours perfecting.Grab yourself a Holley manual and return the 750 dp to factory settings.Nothing wrong with a vac secondary 850 over 427 cid..the engine dictates secondary flow so it is hard to overcarberate,but the 750 dp set up correctly should not be a problem with this CID.

Thanks for the feedback George.

I think you're right :(

just got a call from the body guy replacing the trunk pan. Said when he dropped the tank the fuel line had rubbed a hole in itself, same smell, gas on the a$$

just got a call from the body guy replacing the trunk pan. Said when he dropped the tank the fuel line had rubbed a hole in itself, same smell, gas on the a$$

Interesting. The tank/lines are all new on mine, but I couldn't say for sure that isn't an issue.

It seems to be venting gas out the tailpipes (unburned).

I'll take a closer look.

Thanks

It's obvious where there is wet fuel the leak is nearby. The carb is a long way from the rear of the car :o

Have you checked the gas cap? The 69's are notorious for dumping gas out the filler neck under hard acceleration. Have you noticed the neck is nearly a straight shot into the tank?