[Sauron67MM]

Hello members, I am new to this forum today and would appreciate input in the following area: I have a 70 LT-1 intake(3972110 dated 10/20/69) on my 67 that I believe deserves a proper home. I humble myself by saying performance upgrades are not the area which my knowledge lies. My driveline specs are as follows: 67 327 base 210, .010 over, stock pistons, 63 vette heads, mild cam ( can't locate specs) stock dist., stock exhaust manifolds, Holley Street Avenger 670CFM ( should be 570 ), 2 1/2" Flowmaster w/ crossflow muffler, M-21, 3.08 posi(which will be changed to 3.55's or at least 3.31's.) I know I should run a dual plane and is the popular Air Gap manifold a good substitute? I also have an older Edelbrock Performer but I don't like the fact it is dual duty Holley/Quadrajet. I drive my car, rarely beat it, cruise the back country roads. Or should I just run the Snowflake? Thank you, Scott

[67CamaroRS/SS]

I currently run an Air Gap and I have an issue with part throttle stumble. I have been in contact with Sean Murphy, who used to be one of Jet Performance's carb gurus. He told me my part throttle issue is directly related to the Air Gap feature. For racing it's great, but for street use, it does not allow the fuel to atomize properly at low throttle due to the lack of heat in the plenum. He recommends the RPM(non Air Gap) for street use. You only give up around 3-5hp at max output by not using the Air Gap. Just passing on some info that was passed to me.

[Sauron67MM]

Thanks,I have a stumble as well, but with running the Snowflake. Adjustments have helped, including changing v. adv. source. Other adjusments necessary (jets, timing, etc.) I'll store your manifold advice. Any thoughts on running the Performer as a temp. till I locate what I want? Scott

[67CamaroRS/SS]

The Performer(non RPM) is a good manifold. It makes power/torque from off idle-5500rpm, which is a good street range. How often does a street car really see 5500rpm anyway. For a street car, you want torque rather than power. Torque is what gets you moving and is good for ET's at the track. Power is good for MPH at the track. If I were you, and I am in the process of doing exactly what I am about to suggest. I would ditch the Holley and go with either a stage 1 or a stage 2 Quadrajet from SMI. Go to Sean Murphy Induction and he has a form you can fill out. He will give you his recommendation on what stage Quadrajet to buy. He really knows his s**t. The Quadrajet is probably the BEST carb you can buy for the street. I currently run an RPM Air Gap with an Edelbrock Thunder Series 650. I just purchased a stage 2 from Sean(per his instructions) and I also bought an Edelbrock RPM Q-Jet manifold(non Air Gap). The Quadrajet has small primaries which make it perfect for the street(MPG, streetability) and with its large secondaries, when they open up, the car comes alive. The Quadrajet can be used to build a very nice street fighter and also get good mileage. I think if you go with a Performer(#2101) and the recommended Q-Jet from Sean, you will be very happy. Here is his site. He used to work for Jet Performance as one of their carb gurus and has since left to start his own company. I have to say that he has the best customer service of ANY company I have ever dealt with. His is more than willing to answer any questions you may have and he got back to me in 2 days TOPS. Here is his website:
http://www.smicarburetor.com/

[Farm Boy]

My 327 had a bad stumble on take off. I also had severe clutch chatter taking off in first gear, and a lean surge at cruise speed. The problem was my 670 Holley Avenger was jetted way too lean. I had to increase the primary jets from the stock #65’s all the way to #73’s to get it to run right. I believe these Street Avengers are lean out of the box.

My intake manifold is a Performer RPM. Now that I have the A/F mixture correct it runs great.

[Sauron67MM]

Charlie and Steve, Thanks for advice. I like your suggestion about the older(12 years at least) Performer I have and the Q jet. Clutch chatter aside,I have the exact same problem Steve has but has been toned down with adjustments. I hate the stumble and the surge has to be "maintained". If those are the jets that all 670's came with I shall change those and run it first till $ allow conversion. A buyer for the Snowfalke would help.(that's NOT a plug). So your saying the LT-1 intake does not like the lower RPM's? I also have my vacuum advance hooked to full manifold vacuum which can be backed up by a very reputable source and substantiated by technical data. First I'm gonna order some jets. Seems many complain of "out of box claims" Thanks again, Scott

[pdq67]

210hp/327 stock cam should be the old 195/202, 112/108, .390"/.410", -929 hy-cam.

No, the LT1 intake w/ a TUNED 600 to a 750 cfm vacuum secondary carb like the old Holley 1850 and 3310-2 is fine at low speed's, it's just that it deserves a "more powerful" combination engine, imho!!

You get your 210hp/327 up to 10 to 1 w/ a set of medium or big valve double-hump heads and either Fel-pro's #1094, .015" or stock type .020" thick steel shim headgaskets and it will do FINE!!!!!!!!!!!!!!!!!!!!!!!

Add anywhere from a 268/270/272 cam and a cheap set of 1.625" dia., 4-tube, long headers and it will run like a "scalded-dog"!!!!!!!!

(Fwiw, I'm a solid lifter cam guy b/c these little engines just love to rpm and it will go up as far as you have nerve enough to hold her down!! I've seen 8,000+ rpm out of a GOOD street motor 327!!).. That said a CC 270S or 282S solid cam will do you fine.. 270S for more grunt, 282S for more rpm!

And right too, the old 2101 is a good intake to I figure pushing to 6,000 rpm! I have the old 2101 and a remanufactured Q-Jet that I think is for a 403 Olds on my 406 SB and it does very well considering my stock now medium valve double-hump heads are choking it down, even w/ a 292/230, 109/107, .480" lift hi-cam!

It's now pulled to make way for my 496..

pdq67

PS., my old .040" over, 300hp/327 had a Crane/Cam Dynamics 272/272 Energizer in it and it ran as I said, like a "scalded-dog"!!!!

[67CamaroRS/SS]

I don't see anything wrong with the Performer, old or not. I have done quite a bit of research online and also talking with fellow Team Camaro members and the Q-Jet is the way to go for a street motor. The small primaries make it VERY STREETABLE and the large secondaries make for great power/torque when they open. Plus, if you get the right year, part throttle is adjustable. If I am not mistaken, all the Q-Jets SMI uses are part throttle adjustable, not to mention that with the engine spec form you HAVE to fill out, all your mods are taken into account when Sean designs a carb for you. All this talk about it is making me antsy to get mine and bolt it on. I can't wait.

[Sauron67MM]

I appreciate the input. I no longer am burnin' up the streets. Only beat it once a month or so. I jump in this car for a 2 hour cruise AND take off on 600 mi. weekend trips. I just want to use what I have without changing heads. The cam is not stock(Mild) and without pulling a valve cover for#'s I thought the double hump fuelie 'vette heads I have were better than the stock small valve 210 hp base motor.(help here if you like.) Man who did motor in '95 may remember cam specs (fat chance.) I have beat the --- out of it and its not a dog and 13,000 mi later it is fine except for the above mentioned post. Headers would help flow I agree but I like the stock appearence with dealer installed safety cables and bracket.(I may cave in winter and get them though) Also SMI would require cam specs that I may not be able to obtain. Thanks again. Lookin' forward to improvements.

[rsbecool]

I can provide a proper home for your 110 intake.

[ace's68]

Originally Posted by Sauron67MM

I appreciate the input. I no longer am burnin' up the streets. Only beat it once a month or so. I jump in this car for a 2 hour cruise AND take off on 600 mi. weekend trips. I just want to use what I have without changing heads. The cam is not stock(Mild) and without pulling a valve cover for#'s I thought the double hump fuelie 'vette heads I have were better than the stock small valve 210 hp base motor.(help here if you like.) Man who did motor in '95 may remember cam specs (fat chance.) I have beat the --- out of it and its not a dog and 13,000 mi later it is fine except for the above mentioned post. Headers would help flow I agree but I like the stock appearence with dealer installed safety cables and bracket.(I may cave in winter and get them though) Also SMI would require cam specs that I may not be able to obtain. Thanks again. Lookin' forward to improvements.

If your referring to identifying the cylinder heads you don't necessarily need to pull a valve cover to tell which heads they are, other than valve sizes.

[Sauron67MM]

I know I have 462's from when I bought them in 95 and how do you tell them from 461's. Or if they are X's. When they are installed. Admittedly I'm not a drivetrain guru. Tic-Toc,too old no time. Grateful to the guys who are though. I'm content with the body aspects.

[opelitis]

I would take the car to a trusted mechanic / shop and get them to put your old points distrib. on a machine and take it from there. After 40 years + of gum and gunk you might get a pleasant suprise at how much better the beast will run with the proper advance curve.. B 4 U start changing intakes/carbs I would do the following remembering the engine is not brand new even though she might be 010 over: throw a vaccum guage / compression guage and, if needs be, a leakdown tester to get some idea of the NOW condition of your mill... You might have a "wheezer" and by getting a new intake with a great Q/Jet, B 4 U know your stae-of-tune, you just might be disappointed. Do it once so yah don't have to dig deeper and do over it again..

[Sauron67MM]

Thanks. Point noted. Excecution of members suggestions after evaluation process begins on my end. I may have overstated my lack of knowledge in drivetrain aptitude. I do my own mechanical work ( machining and other things aside) and bodywork to show quality standards. I just don't know the complexities of different aspiration upgrades and techniques. Regarding Oelitis' statement, Yes the dist. has 46K known mi. on it. I believe the off idle stumble might be corrected with dist. upgrades and proper Avenger jetting. The stock 210 horse dist. not applicable to the upgrades my motor has received? ( jump in here again ). I also feel comfortable with using my old Performer as a replacement for the Snowflake as Charlie says, even though it is a combo square/spreadbore model. Compression / Leak down test sounds good. Brick By Brick as they say.