I sold my top end that I planned on putting on my 400 to go a different route (mainly trying to make competing with my dad fair; who's running a set of hump heads, 1.94 intake, milled to 62cc and ported/polished, with a .480 lift strait cam, and flat tops behind a 355.) If i recall correctly his heads flowed 280-290ish cfm.

I have a set of 2.02 intake hump heads casting 3782461. I plan on hand porting and polishing them myself with the help of my dad. I want to run a comparable cam to his behind my 400.


Do you think its reasonable to expect 400-420 horses on this combination? Or should I sell the heads and do the same thing to a set of vortec heads?

 

No offense, but I have a hard time believing that his heads flow that well. I have a set of 186's, that flow 270, and I had to bust out the epoxy, and bolt sleeves to get that to happen. Across a 1.94 valve your doing good to get 245-260 in a 4 inch bore at .500" lift. I have never ported 461's specifically, but I have a set RHS ported for a much older freind of mine who use to race pro comp dragsters, and those heads don't even flow that well. Furthermore I would hesitate to tell you to use factory heads especially that old, just because all the numbers matching guys like to collect those for pretty good coin. I'd invest in a head that flows better than those would ported like Dart Iron eagle's that way you can control chamber size, and use them over, and over again without cutting up those 461's

~Couch

 

well with the info i gathered up the vortec heads will be the better way to go.

stock 461 flow at .500 lift 216cfm on the intake and 137cfm on the exhaust.
ported 461 flow at .500 lift 224cfm on the intake and 162cfm on the exhaust.
stock 855 vortec flow at .500 lift 239 fm on the intake and 147cfm on the exhaust.

i got the 461 numbers on this website. http://racingfeed.com/downloads/chevy_flow_data.pdf

and the vortec numbers from the small-block chevy engine build up book.

 

be weary of core vortec heads they are often cracked it's costly to repair them, but if you buy them already repaired they are usually very affordable, and fixed permanatly. If you buy a set I would go that route. Just shop your local machine shops, and see if anyone has any repaired 062's or 906's. The 062's supposedly flow better I think they are about the same, but 062's just look cooler.

~Couch