1st design off road cam #3927140 Vacuum Issue?

**cdn454LS6** · #1 04-30-2009, 05:50 AM

Hi Everyone
Rebuilding my stock 302 with all the original parts, pink rods, 1178 crank, 0 rockers, 11-1 stock pistons, single DZ carb etc etc.
Can I use the 1st design off road cam #3927140 in this stock engine for street use with 410 rear.
Can I still use pump gas 94 And is it possible to have a vacuum problem at all?
Thanks very much in advance for your help.
Ken

beater68427 · #2 04-30-2009, 06:27 AM

My JL8 has that same cam seems to work fine I actually like the bleed with the overlap seems to be a bit of a ease with the comp ht. with pump gas, no ping brakes work great!!

**Bill Pritchard** · #3 05-01-2009, 08:50 AM

In the mid 70's I built an LT1 with that cam and had it in a 69 Camaro with power disc brakes. Had no lack of vacuum for the brakes, so you should be fine.

Andy · #4 05-01-2009, 09:00 AM

A guy on camaros.net just put one in his car along with headers and he loves it. It really sounds strong in his video. I think he has a gardeners chambered exhaust too.

https://www.youtube.com/watch?v=WTgT0VCytGc

https://www.youtube.com/watch?v=iXK-lTkRXBY

**Salvatore** · #5 05-01-2009, 02:46 PM

4:10's may be a little tough to pull out with the car. Unless the trans was a M20 box. I would go to 4:56's with an M20 box and that car would be mean. Also I like pressed in wrist pins. A little safer and it doesn't have much, if anything to do with performance. 302's are all about proper gearing. We already know how much they rev!

Steven J · #6 05-01-2009, 06:54 PM

My brother had a stock, except for the off road cam, 70 1/2 Z-28. 4 speed, 4.10 gear. It was fine with power brakes, had a great sounding idle, but 4.56 gears would have been better with that cam.

**Bill Pritchard** · #7 05-01-2009, 10:56 PM

I agree, a steeper gear would be better...I had 4.88's in my 69 Camaro.

**Salvatore** · #8 05-01-2009, 11:10 PM

Now we are talking. On a sb chevy most people play under the hood instead of playing under the back end!

70 ls6 convert · #9 05-03-2009, 07:34 PM

Thats the cam i put in my 302 back in 1990,its been foulen plugs ever sence,turns out that was a good thing because i never drove it.just wondering if the primary jets is the cause of the engine running so ritch..

**1967Z28** · #10 05-04-2009, 12:01 AM

I ran that cam in my 302 for a number of years and loved it. Never had a detonation problem using pump gas premium but it did tend to foul plugs. I drove this car as a daily driver and would change plugs about every 1000-2000 miles. No vacuum problems at all. My engine was stock other than headers and the cam, and I was running 4.10 gears. I think 4.10 gears were great with that engine. Best to run 302s with a 4-series gear. I don't think you should run the 140 cam without headers. Chevrolet certainly did not recommend it back in the day. Is that what you are considering?

-Jon

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