Mr. King

OK, I'm trying to decide now between these two cams for my 1966 Cutlass. It's a 1967 330 bored .30, 9.0:1 compression, Edelbrock Performer RPM intake, Edelbrock 600 or 650, Muncie M21 4-speed and a 3.23 POSI.

What would you put in it?

Mondello JM 18-20 LIFT .488/.496 DUR 216/226 LOBE SEP 112 degrees

or

Mondello JM 20-22 LIFT .496/.512 DUR 226/230 LOBE SEP 110 degrees

Will I need to change anything in the valvetrain with either of these cams?

I'm going for an all around street muscle car with a slight lope.

Eightupman

Neither. You are porbably better off going back to Edelbrock since you have the intake and carb already setup. They would have the perfect cam grind for it. #3712 is the part number to compare specs.

John

Redog

You will have to change the whole 9 yards

Mr. King

Redog....I'm not sure I understand your post "you will have to change the whole 9 yards" Are you talking about new rockers, springs, pushrods...etc. Or are you talking about the rest of my set up.

I was also looking at the Edelbrock Performer Plus cam with Dur @ .50 204/214 lift 448/472.

Or a Crane Cam with Duration @ .050'' Lift: 204° Intake / 216° Exhaust
Valve Lift w/1.6 Rockers: .456'' Intake / .484'' Exhaust

Or I have a very small "stock" cam with these specs: DUR @ .50 187/200 LIFT 400/402

Redog

I was just talking about the rockers, spring and pushrods.

It really depends on much much more lift you are going to have. I would just play it safe and do everything with the cam swap

Mr. King

Cool. THANKS!

70Wcars

I have used the 18-20 in 455 cars with good success...in your small block you will feel a noticeable lope at idle...the 204-214 cams are nice, I have one in a 69 350 and idle is smooth...I also agree that you should change springs, but don't go crazy on seat pressure...around 100 lbs. closed is fine...also switch to a 5/16 dia. Moly push rod...stock length should be okay for either cam...new rockers to replace worn originals and you should be good to go.

soocutlass

I would go with the edelbrock RPM pakage. I put a Lunati 488/496 lift cam in my 71 350 with flat top pistons 10.25:1 and it goes good. I had to install longer push rods to compensate for higher lift and smaller journal diameter. Check with your supplier to make sure the compression ratio is high enough to support the longer duration of the RPM PKG. Just to let you know I installed a Edelbrock performer package on another Olds motor and i was not happy with the performance.

Mr. King

Thanks for everyones help on this one.

I shouldn't need to change any other valve train items because the motor was rebuilt less than 500 miles ago. The #4 heads were rebuilt with new valves, performance springs, new rockers and moly pushrods.

What do you guys think of this Comp cam:


Duration at 050 inch Lift: 212 int./218 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.453 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.456 in.
Lobe Separation (degrees): 110

Plus, it's pretty cheap at $125

70Wcars

Not a huge fan of Comp. I have heard of failure from other Olds folks. That being sad, the specs on that cam sound nice for a slight " muscle car" lope at idle and useable street rpm power range. I think Crane offers a similar grind.

iam2fast4u86

How does the 18-20 sound and perform in a 455?

redoldsman

I hope you get a response. This thread is over 12 years old and 70Wcars has not posted on here since April 2015.

68f8t5

I would reach out to CutlassEFI, to see what his thoughts are. He has helped many on this board. Just my 2 cents

jensenracing77

X2. There are much better cams available today.