street cam for 360 magnum

mtolley said
cost on this swap is why i ask about hydraulic flat tappet cams, trying to keep the cost down. knowing the springs will need to be replaced as well as other parts, it pushes rollers way on up there. just figured while the intake and front cover were off id put something in there besides a broom handle. if i remeber right cam specs on the flattys are based on 1.5 rocker ratio and magnums are 1.6. so anything i choose will have more lift than advertised. how much lift can a stock long block handle before things get too close? what springs to use with magnum heads and flattys? what pushrod lenght? it will need enough vacumm for power brakes all help is really appreciated! mike t

About .520 lift, mine had about .020 clearance between the bottom of the retainer and the top of a valve guide on a .512 lift cam which I degreed to verify the lift. For about 140 bucks you can get the single set of springs from Hughes good for .550 lift and their retainers and locks which. will solve the clearance problem. Several other members have experienced the same thing. I used on of those $20 valve spring tools and did it right on the heads in the car. Good luck, the magnum is a fine engine ,If you decide on roller rockers use a chevy stud with chevy 1.6 roller rockers. best results have been not from the stock guide plates but ones from older oldsmobile v8's. The stock ones allow too much side to side travel with a chev rocker. I have heard of several instances where the comp cams kit to swap to flat tappet has been problematic with issues with preload on the lifters which were subesequently were noisy. There apparently IS a differentce between the AMC lifter which now lists right alongside mopar hyd lifters with the same part number, I do not know what the difference is but apparently their use is best over the Mopar lifter. If you are sure on a flat tappet you will also be prepping the oil holes in the block unless you have the early magnum block which has BOTH oiling for roller or flat tappet. There are no cheap brand new magnum cams out there, regrinds or grinds off of factory core yes. Youre cheapest bet is a 150 dollar regrind and Hughes springs retainers about totalling about $300