[Jay S]

Usually the tight lash cams are more aggressive. They loose less duration with less lash, but they also have quite a bit less seat timing. Against a hydraulic cam another 15* @.050 is not far off, even though it is only loosing 8* taking up the lash, the shorter seat timing reins in the power band. The short seat of the Comps XE cams act similar, they won’t turn that many RPMs for how big they look at .050”. XE 274 often run out of steam before 5000, I recall an out of the box KRE d port dyno even maxing out HP at 4500 RPM. The bigger 284 is usually done before 5500, it will probably have no issue making 500 HP, but there are better cams. Some of the SFT designs that have bigger lashes often have quite a bit more seat timing, and the 10 degree difference to the hyd cam hold pretty close. Not to easy to compare, often guys end up to small on their SFT choices..

I thought that Bullet Ultradyne grind Steve brought up was a really good pick. If you talked to Tim at Bullet I doubt he would make much for changes from that in a SFT. I’d probably suggest a wider LSA since the car has a low stall and highway gears, Tim likely would also. Those profiles are easy on parts, don’t need a ton of spring pressure, and make great street cams. I’d take out any XE HFT and swap for one of those Bullet SFT grinds in one of my cars in a heart beat.

Bullet has some HFT cams that work well also. Some high rpm cams similar in size to the .050” ratings of the XE 284 but have quite a bit more lobe lift, IRC they are .530+ with 1.5s. My go to HFT profiles at Bullet have been their .3334” lobe series. The 283* @.006” , 235*@ .050” paired with 291* @.006 and 244* @ .050” end up having .50” lift with 1.5s and .550” with 1.65s. It lopes some when ground on a 112 LSA, but overall a lot better cam than the XE284. We did a 280/288, 232/240 in 112 with 1.65s (.550” lift) for a GTO 455 with 3.07 gears and a 2500 stall. It barely lopes at all, drives around like it has a stock cam, but when you open the throttle, you quickly realize it is not a stock 068 cam anymore!

Worth a call to Bullet, at very least you will have something to compare with what Butler sells.