Thanks Dwight,
I know that the present '69 Chevy 427 combo that is being run at 445 hp has an 830 cfm vacume operated secondary carb on it. I did not know of ANY combination in the stock eliminator classification guide pre-1970 that came from the factory with an 850 Holley Double Pumper Carburetor.

Jim Cimarolli

For the 69 ZL-1, NHRA lists the Holley R-4296A. Holley lists the R-4296 as an 850 double pumper. Shows a 0.025 primary squirter and a 0.035 secondary squirter, and a 4150 series, with metering blocks front and rear. Shows it to have 1.750 throttle blades and 1.562 venturis. Same carb is listed for the 69 L-88.

The ZL-1 is rated at 445HP by NHRA, and the L-88 at 440HP.

I will say I've seen several carbs for sale listed as L-88 and ZL-1 carbs that ARE vacuum secondary.

Supposedly at least some of the ZL-1 cars were delivered with the R-4346A carb that came of the L-72 427-425HP cars, and the carbs had to be swapped before they could race.

Alan Roehrich


Bring "AA" classes to NHRA Stock Eliminator!

Thanks Alan,
Will NHRA allow a double pumper carb on the ZL-1?

Jim Cimarolli

Jim,

Are you still on here?

Sherrie

Can anyone tell me where I can find some info on the race that's going on right now in Tulsa?

Sherrie

The FastNews guy probably won't be there until tomorrow.....

Thanks but I finally found out the results. I just thought they were posted somewhere and I thought Jim might know but I guess the 'ol man went to bed?!

Sherrie

JIM, Alan is correct, 69 L88 vette and the ZL-1 Camaros can run an 850 DP

bp4133 Bob Pagano

Having not carried ours to the track yet (it ain't even on the dyno yet) I can't tell you what tech is accepting at the track, only what the rulebook and the blueprint sheet call out, and what the Holley tech guide says. The only person I know successfully running a fast L-88 in NHRA is Steve Calabro, maybe Steve will drop by and say what is on his car.

Again, I have SEEN vacuum secondary 850 carbs CLAIMED as correct for the 1969 427-430HP engines, and been told they are legal. The new looser rules on carbs MAY mean you can run either or, provided it is the correct size and model. Maybe Travis will check in again and give us another clarification.

Alan Roehrich


Bring "AA" classes to NHRA Stock Eliminator!

The '69 L88 and ZL1 carb was an 850 DP. The R-4296 that is listed in the blueprint specs is described by Holley service manuals as a DP and if you have ever seen a restoration you know that it is. The '67 and '68 L88 engines (R-3418 and R-4555 Holleys) were 850 vacuum secondary carbs.