Which cam for a 351 Cleveland? What five dyno sheets say
Every Cleveland cam thread ends the same way: someone says "it depends," and it does — but not on opinion. Five engines have been dynoed in public with the cam as the variable or the cam clearly stated, and between them they map the whole street range. Here is what they show, cheapest to wildest.
Factory Boss 351 solid grind — 290/290 advertised, .477" lift, 116 LSA
On Holdener's replica at Westech: 383 hp / 391 lb-ft with headers and a 750. On the Speed Secrets test engine: 397 / 401 with a Performer RPM. Wide lobe separation, low lift — it is a smooth, high-rpm factory grind that leaves airflow on the table in a 4V head. If you have one, it is worth keeping for originality and not much else.
Lykins custom mild hydraulic roller (specs not published)
On a stock-head, stock-iron-intake 1970 4V at under 10:1: 433 / 428 on pump gas. This is the sleeper. A hydraulic roller lets a mild duration carry lift the flat tappets cannot, so it makes torque at 4,000 and horsepower at 5,600 without the idle of a bigger cam. If you are ordering a custom grind for a street 4V, this is the target.
COMP XE284H — 240/246 at .050, .584"/.588", 110 LSA, hydraulic flat tappet
Two dynos, two shops: 451 / 411 (Speed Secrets) and 450.4 / 411 (Holdener at Westech). The most-proven street/strip cam on a Cleveland. It gives up the bottom 500 rpm to the Boss grind and takes back 54 hp on top. Needs springs; the factory set will not clear the lift.
Solid flat tappet, 250–260 at .050 class (Competition Engines 408, specs not stated)
588.5 / 536.4 on a 408 with tongued iron 4V heads, pump gas. The stroker makes the cam livable — an extra 57 inches turns a cam that would be peaky on a 351 into a 536 lb-ft street engine.
Solid roller, 259/267 at .050, .717"/.731", 108 LSA (Lykins 354 race engine)
614.8 / 467.6 at 8,000 rpm on iron 4V heads and race fuel. This is the ceiling of a factory casting, and it is a race cam with race maintenance.
Three rules that fall out of the list
Lift does more for a 4V head than duration does. The roller cams win at every level because the port has more to give at .600" than at .480".
The springs are part of the cam, not an accessory. Every one of these engines was tested with springs matched to the grind, and the two test engines that changed cams changed springs first.
The dyno gain is always quoted with a tune. The Speed Secrets engine was re-timed and re-jetted between cams. Budget for the dyno day or budget for half the gain.
Use the calculator to try any of these on your own parts list — the cam dropdown has all of them except the two custom grinds — and watch the rev-limit readout. If it says the springs are setting the peak, the cam is not the part you need to change.
Try a cam on your buildSources: Richard Holdener (Westech, STD) — Boss 351 replica; 351C intake test. Speed Secrets — 351 Cleveland cam test (SuperFlow, STD). Lykins Motorsports — 1970 351C 4V (Dale Meers Racing Engines, STD); 354ci race engine via DragBoss Garage. Competition Engines — 408 Cleveland (SuperFlow, STP).