Hey guys, we are building this 383 for our 68 convertible could someone desktop dyno it please
383 steel crank
5.7 rods
KB 100 flat top pistons 10.9 compression w/
64cc small valve camel humps pocket ported
comp cams 280 magnum 230/230 @50 480/480 lift
110 lobe separation
or comp cams 270 224/224@50 470/470 lift 110 lobe separation
RPM intake, 770 holley steet advenger
700r4 with 373 12 posi rear
Thanks in advance, mike

[This message has been edited by mike's 68 (edited 11-23-2002).]

can't really tell you too much because the head work will make my estimates way off. Using a "dual plane" intake and "headers with open exahust" the 270H cam numbers spit out 353 horsepower @ 5000rpm and 452 ft. lbs. torque @ 3500. With the 280H, 370 horses @ 5500 and 455 ft. lbs. @ 3500. Didn't give up much low end according to the program. These numbers are with 462 casting heads.

thanks was hoping for a little more i think the heads are holding us back but want to retain them for car show judges. the tork looks ok any one else running this combo if so how dose it preform thanks mike,68

[This message has been edited by mike's 68 (edited 11-23-2002).]

I get 385 HP at 5500 RPM and 429 FT/LBS @ 4000 RPM with unported Camel Humps. Port work should in theory bump it up another 25HP.

By the way. You will have pinging problems with iron heads and 10.9:1 compression with that cam. Unless - you plan on running race gas. If you plan on running pump gas you need to run a full point lower compression.

thanks eric68 did you run that with the 270 or the 280 mag cam heads are ported & 3 angle valve job thanks again

Comp 280H.

"ported" means nothing to me. Porting can hurt flow if done wrong or help a bunch if done by a pro. Do you have any numbers from a flow bench? That's the only way to get real power numbers, and then they are only Desktop Dyno numbers.

A good port job on your heads would extend the usable power band to closer to 6k and give you a few more peak HP (again - if they were done right). From the looks of DD2k this motor would be "flow limited" with unported stock heads at about 5500 RPM.

[This message has been edited by Eric68 (edited 11-25-2002).]