G'day all im fairly new to the forum and would like some help if possible, ive been slowly doing up my xd for a while now and its close to being ready for inspection and rego im wondering about the output of my engine the specs are as follows-4 bolt 351,mildly ported 2v heads,4v valves,double spring(crow) Y.T roller rockers, edelbrock F351 2v manifold, extractors,crow cam (21686) hydraulic

lobe seperation 108
inlet lobe lift .2900
exaust lobe lift .2900
advertised duration 280 (in&ex)
inlet & exaust valve lift .5017
A.B.D.C .050" duration 224
A.T.D.C .050" duration 224
advance ground on cam=1 degree
inlet lobe lift at T.D.C on overlap .057

holley 750 vac sec
7 litre super sump

If anyone could give me a rough estimate of power and more importantly torque would be much appreiciated. thanks in advance

I'd say 270hp at the tyres or thereabouts. And approximately 320-330ft/lb?

Wh comp ratio are you running??? What ignition system??? Has the dizzy been regraphed??? Are the extractors tune length or try Y's???
Is the inlet manifold a dual plane or single plane???

Hi guys thanks for the replies so far.

cjh, the manifold is a low rise dual plane the ignition is basicly factory electronic with pretty much all new components. the extractors are older type ones that ive had for a few years now but apear to be tuned length they go 4 into 2 then to the collecteres which are 3 inch.
as for the comp. ratio honestly im not sure, when the heads were done they were just milled slightly more than required to be flat(for lack of a better word)

thanks again hope this info helps

So, the extractors are not 4 into 1's??? The manifold would be better if it were a single plane, and you'd also make more power with the dizzy regraphed and an MSD 6AL ignition unit fitted.
A normal 351 was only about 8.8:1 comp ratio, so with that cam you have, 9.5 to 10:1 would be better.
Then you would be punchin out about 370 to 400 flywheel HP.
Currently you would have about 280 to 320 flywheel HP.

I would say they have played with clevos before and just know what power each combo will roughly make.

Put it together, put it in the car, drive it to a dyno shop and find out. Dont be frightened now, you have to have a starting point. Clevelands are very responsive to the right type of knowledge and be very clear when selecting camshafts. Its all about airspeed and compression with clevos so do your homework. Chev or Windsor catalog combos will result in a clevo you wont be happy with. A good dyno tune/ diagnosis will set you on the right track. Ive been there, and its a long process and Im still learning. But they would have to be the most characteristic small block in Australia. Luv em.

Hi guys thanks for all the replies.

I have a bit more ifo and a couple of questions for you, firstly i think from memory the heads had about 20 or 30 thou skimmed off them they said they woulnt take too much or id have problems with valve train geometry they are also closed chamber.

Secondly does anyone else have trouble with their roller rockers being pretty noisy? being hyd. i know that i cant ajust the lash as such but i have noticed that they have a bit of play fom side to side thought about running a thicker oil but not sure which to go for.

Thirdly can anyone tell me of a good reputable tuner down here in hobart tas. unfortunatly we dont have much for high perfomance work d own here that i know of.

Any help would be great thanks.