Cam for 428

[428Marauder]

I’m about to paint my old Merc that has a service block 428 and a C6 in it with a Pertonix distributor and I’ll have some funds left which is good because it’s actually pretty slow. Has regular FE heads on it and an aluminum modern Holley with electric choke. I’ve got some 1965 Mercury Marauder 390 heads, shop said $750 for a rebuild on them. Probably go with an Edelbrock Performer intake and use the same carb I already have. Need a cam. I’d like for it to sound really choppy and otherwise be a good street cam. Figured this would be the best place to ask. Open to other ideas. WWYD with $2500ish to spruce up and old 428?

TIA

[Joe-JDC]

Stay away from the Performer, go for the Performer RPM instead even on stock camshaft engine.  The Performer has a couple of ports that flow less than 220 cfm.  Joe-JDC

[428Marauder]

Any thoughts on the knock off intakes that are about half the price?

[blykins]

I've got cores in stock for both flat tappet and roller cams.

[Riderjeff]

Have Mr. Lykins spec a custom cam, they’re not too spendy and will be guaranteed to synch with the rest of your combo. Make sure to rebuild the heads with springs that match the cam.

Reports are the knock-off intakes actually work pretty good, watch out for porous castings.  You might get lucky and find a decent used performer RPM.

[hbstang]

+10 on rpm intake and hyd roller cam.228-232 @ .050 lift  .550 would run and sound great!

[428Marauder]

What kind of springs should I use on the heads to best match with Mr. Lykins roller cam?

[blykins]

Can’t choose springs without knowing the cam. 

Just know if you go hydraulic roller, the steps around the guides will need milled down flush, so that a locator can be used.

[428Marauder]

So, sounds like it would be best to get the cam and then have the heads rebuilt to match, right?

[blykins]

So, sounds like it would be best to get the cam and then have the heads rebuilt to match, right?

I would have all machine work done first, so that you can get an accurate compression ratio measurement.  Cam needs to be ordered pretty close to last, when you have all your build specs in front of you, including compression ratio, new valve spring install heights, etc.  Then when the cam is chosen, you can order valve springs/retainers/locators/locks to assemble the heads.

[My427stang]

I agree with Brent on the heads and Joe on the RPM intake.  All good.

Cam choice based off of:
- Heads, intake and exhaust flow
- Desired HP/TQ peak based off those inputs
- Desired other behavior (idle vacuum, idle quality, etc)
- Weight and gearing
- Tranny
- Use of the car

Then, you design the cam, get springs to do what you need in the resulting installed height and max lift, and buy pistons for the compression and valve clearance the cam and valve size it needs. 

So you really have to start with the heads and intake, at least up to valve job, decking, etc or you can't calculate the next steps.

Once thing I think that makes life MUCH easier though, especially if going roller, is to cut the spring locating boss off the heads, replace the valve guides and use a spring cup or ID locator.  It really makes setting installed height and spring choice much easier.  At that point, an 11/32 valve can be a benefit too, but it's even worth it with a 3/8 valve.