bams12

I was wondering if the Edelbrock performer RPM intake will fit under a stock 80 hood ? I have no problem going to a drop base breather to make this situation work. I would also like to go to a Demon carb. The cam that is spec'd to match this intake has the following specs. Duration Advertised 308/318 @.050 234/244 Lift @cam .325/.340 @ valve .488/.510 . I know there are guys out there that know what this cam would idle like. Is this a very lopey type idle or not?Please comment . If I could get the Performer RPM to fit under my hood and not idle too rough I would probably go down that road. If not I have to go with the Performer with cam #'s Duration Advertised 278/288 @.050 204/214 Lift@cam .280/.295 @valve .420/.442 Please comment I need all the advise that I can get because these cam spec's are Chinese to me. Brent

hawgn68

The performer RPM will fit with a drop base air cleaner. The RPM cam will have a big lopey idle and you'll need at least 10.0:1 compression to make it work. Unless you've done some head work or have aftermarket heads (cam, heads and intake all have to work together with your CR), you're better off with the performer package of intake and cam.

Jimbo

bams12

I am looking at the total package with aluminum heads etc. So the performer specs for the cam is a decent performing cam with not too much lope? Brent

brooksman9

lebvette

It will fit with a drop down cleaner. Larry

Ganey

Engine, trans. & rear gears at least should be stated for cam.

You would need a manual trans. like the 4 spd. or a high stall converter if auto. for the RPM cam. (@.050 234/244) Many would consider "very lopey."

More cam than the Performer (@.050 204/214) could be run. Expect smooth idle.
Edelbrock is known for intakes & heads.

bams12

In my quest for a good top end kit its like the three bears story . This cam being to lopey , this one too smooth which may be the case in the edelbrock performer and performer rpm. I have since discovered the Trick flow top end set up . Its cam being 210/216 duration at.050 and .440/.454 lift. Would this combo be a nice trade off of respectable hp\tq and a middle of the road idle. It requires the eldelbrock rpm intake a holley 600 cfm and 9.5 to 10 cr. Brent

jackson

bams12:
Which motor does your 80 have? ... 305" LG4, 350" L48, 350" L82? ... /ganey ... what trans? auto/manual ... what rear gear ratio?

OE L48 has dished pistons (about -10 to -11 cc) OE CR about 8.5:1 ... 64cc heads will bump CR to about 9.5:1.

OE L82 has flattops (about -5 to -6 cc) OE CR about 9:1 ... 64cc heads will bump CR to about 10:1.

Many folks would advise against spending alot on heads for 305" LG4.

You need to know what your present CR is in order to figure what it will become ... choose CR first ... then cam to match. More likely than not ... Performer cam is too little and P RPM is too big.

bams12

My motor is a L-48 however it does have 4 bolt mains and it is numbers matching L-48 block for a 1980 . The transmission is a turbo 350 stock torque converter , what ever that was. The rear I redid last summer and swapped the 3.08 for a 3.55 ratio. I too think that the performer may be too mild and the performer rpm way too radical. That 's why I posted the figures for the trick flow set up because they seem to be a cam profile that is in between the edelbrock grinds. I plan also redoing the bottom end to 9.5 CR when I redo the top end. Brent

Ganey

Yes, that's a much better match for your setup.

ylose

With the RPM package, you changed your rear gears which will help but you will need to install a more correct trans stall for the application. Otherwise you will fall on your face off the line, unless you stand on the brakes until the RPMS are up to par.

RPM is very lopey, which is why I like it. It requires decent gearing and stall to compliment the package.

MYBAD79

The RPM cam requires at least 9.5:1 compression. I had that cam installed when I bought my Vette, with the 64cc heads the CR was still below 9.5 and the engine did not run very good. I did however like the idle sound very much
I installed the Performer cam and the engine runs a lot better, however, this cam is a little too mild, you get a lot of low end power but nothing at higher rpm. There are many better cams on the market

jackson

Would someone please comment on rarity of numbers matching L-48 having 4 bolt mains?

MYBAD79

Maybe somebody installed splayed main caps ???

maybe somebody machined the block to install the 4-bolt mains ???

... or somebody re-stamped the engine block

Ryan77

I had an RPM with a Holley street avenger carb and a 1-1/4" drop base air cleaner with a 3" filter, it fit under a '77 hood.

bams12

I thank everyone for their input , it has helped alot. In summary it looks as though the RPM intake should not be a problem with a dropped base air cleaner. The performer set up is probably too mild , the RPM set up being too extreme. I think the Trick Flow cam profiles sound like what I am looking for. I called their tec line and the rep said it is a nice throaty rumble from the rear exhaust area but not an uncomfortable idle. He said ,he has a relative who put that same set up on his 350 with an RPM intake and 1406 edelbrock and it idles nicely with lots of respectable output. As for the matching L-48 block it does not have splayed on caps , it looks to be factory. I asked this question on the forum about a year ago when I discovered this situation . A forum member said he used to work on the GM line and if they ran out of 2 bolt blocks for the L-48 cars it was not uncommon for them to grab a 4 bolt L- 82 block to keep the line moving. Sounds plausable to me . Thanx Brent

MYBAD79

That does sound plausible

That trick-flow cam, is that this one ? 210/216 duration at.050 and .440/.454 lift ?? I think (not sure) that this is still less than the L-82 cam ??

Lunati has interessting cams, their "Vodoo" series seems to be pretty good, there is one with 222/230 duration and .470 lift

bams12

I will do some hunting in my aim to see if the cam spec's are listed. Is there really any difference between two cams with identical grind numbers but made by different companies ??Brent

MYBAD79

Maybe (and that's a big maybe) there are some quality differences... Su**** for example has it's own cams that have the same grind numbers as Comp,Crane,Edelbrock for a lot less $$

bams12

I see what you are sayin' " wink wink nod nod ". I looked through my mound of corvette books and could not find the specs for specific cam grinds. If anybody knows how to access that I would be interested. Lastly I checked my block number and it is 14010207 which in my books indicates it to be a 1980 L-82 block but the car has none of the L-82 tell tale options or indicators. Brent