Advice needed - 428cj flat tappet or Roller Cam - answers on a postcard....

[jiffy]

ok, my 428CJ is in finally getting rebuilt, it's not been a rush job (14 years and counting...)

It's +0.040, 10.6: compression forged pistons, Scat I-beam rods, pretty much standard heads and valves, and the rear gear is 3.0:1 with a RUG AE2 CR toploader, OEM carb and exhaust.

So - I have ordered and received my cam - it's a Lunati flat tappet cam and lifter setup, IIRC these are the specs:

 Hydraulic Flat Tappet Cam.
•Advertised Duration (Int/Exh): 268/276
•Duration @ .050 (Int/Exh): 227/233
•Gross Valve Lift (Int/Exh): .552/.564
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 1600-5800
•Includes: Cam & Lifters (#71949PR-16)

 Part Number: 10330703LK

 My springs are good to about 0.600 lift and are at 380lbs at .56 and in theory should be fine for this cam. I have standard hydraulic rockers, and I have just replaced the shafts with new, aftermarket shafts, so they SHOULD be good.

 I have received a fair bit of advice to go roller cam and lifters, not just for avoiding the chance of flattening a cam lobe, but for more power. I'm limited in terms of lift with the springs I have (0.600) so the target replacement roller cam would be a Howards Roller cam:

Ford FE 352-428
Cam Series: Retro-Fit
Advertised Duration: 288/294
Duration @ .050": 235/241
Valve Lift w/1.75 Rockers: .560/.560
Lobe Separation Angle: 110
Intake Centerline: 106
Valve Lash: Hyd./Hyd.

SO - THE QUESTION.
Should I stop the builder assembling the engine (supposedly in the next week or so) and get this roller setup, and if I do, will I need new springs and if so, how much pressure do I need, AND will the roller cam described offer noticeably more power (or is there another cam I should be considering,

OR

am I over thinking this and the performance gains are small for the monetary outlay and if I remove the inner springs and run the flat tappet cam/engine in properly, then I should be ok.

 H E L P ! ! ! !

[blykins]

Answered on the other forum....but I'll copy and paste here too:

Well I did that, but noticed that you changed the roller cam specs.......I'll have to take another look.

The first cam is a no-no though.

[blykins]

Where would you like to be on horsepower rpm peak?  5000-5500?  Running power brakes?

[jiffy]

Thanks for responding.

Apologies for the confusing change in roller cam specs. I did think the original roller cam spec was a little too tame.

Running power brakes, power steering, '69 mach1, CJ heads, about 71cc.
Dunno about the deck height.

Copied and pasted from my other reply -

So - what sort of spring pressure should I be shooting for when open?

I'll also get the EXACT cam spec package from the box.

So - just at first glance, going the roller approach COULD net some good power in a OEM-appearing package, but I seem to have cobbled together a bunch of parts that aren't well suited (now, that's no surprise)

It would appear my options are:
Get a better hydraulic flat tappet cam (suggestions welcomed) and lower the valve spring pressures. Be careful when I run it in. I can then keep the pushrods, rockers, lifters, cam gear. Car will be an occasional weekend driver, not race car.

Go hydraulic roller - could keep the valve springs. Get new cam (suggestions welcomed again), lifters, pushrods, distributor gear. Make a little more power, be safer.

What sort of power am I thinking - probably in the early 400's on a good day, all over by 5,500 or shortly thereafter, assuming I have all my other crap together. Correct my thinking if I'm stupid.

Please help, it's obviously and clearly needed!!

 Thanks for the info so far - destination car is a '69 Mach1.

 Jeff, Australia.

[jiffy]

Final points - fuel here in Australia is 98RON, I believe about the same as 90MON or in the US about 94 (R+M/2)
 -
Does that help, or just confuse things?

I have a few sets of springs here - I could get the ones installed changed out for a set with lower pressures - what should I be shooting for? I don't really want to change the whole direction of the cam/lifters/springs/pushrods/dist gear etc at this late stage, so I'm thinking that a flat tappet approach is more sensible.

[blykins]

I'm gonna reply to the other forum just to make it easier.