406 small block chevy

holley 650cfm 4150 DP
performer rpm intake
sportsman II heads, 200cc, iron, 72cc angle plug
2.02/1.60 manley street flo valves
10:1 static compression
comp XE274 cam 274/286, 230/236, .487"/.490" 110 spread, 106 intake
or comp XE284 cam 284/296, 240/246, .507"/.510" 110 spread, 106 intake
*should I go solid?
floating pistons 030 over on 5.7" rods
3.75" stroke crank
1 3/4" long tube headers
HEI distributor, solid copper core wires, accel shorty plugs

Any guesses? How about suggestions for improvement?

Thanks!

Just guessing here, but, I'd say no less then 380hp and no more then 430hp at the flywheel/flexplate, depending on how your combo reacts and take that small of a carb. If you were to put a good 750cfm carb, I'd say more around 420hp maybe more with fine tunning. Looks like your setup is similar to my 388ci, except for your smaller carb, but, better flowing heads. Good luck! graemlins/thumbsup.gif

I also have a 750 vacuum secondary holley, but it needs a few more parts before it can run well with my motor.

What heads are you running? I was thinking of picking up some AFR 195 heads but I can't seem to find a source for good, used ones. People must really like them enough not to ever sell them :D

I've also been contemplating what Harold has been reccomending to the other guys with 400s, the 401A6 Lunati cam. I wonder if it's worth anything over the Comp XS274.

Sounds like I'll be missing my goal of 425hp/475tq :-\

Any suggestions what else I can work on changing?

you will see about 30HP more by going solid. I have run a xs268 and xs282 in a 355 and 388. Had great success with both. Much better than the xe grinds

Originally posted by smog test reject:
What heads are you running? I was thinking of picking up some AFR 195 heads but I can't seem to find a source for good, used ones. People must really like them enough not to ever sell them :D I've got some plain ole Bowtie heads that have been ported and fitted with 2.02/1.60 valves. I know what you mean tho about those AFRs...that's what I want. My heads are ok, but they need some work...and rather then pay or do the work myself, I'd rather buy some new ones that flow better and slap them on. As for your cam, I'm not too sure on what would be better, I do know that solid cams always "free up" more hp, but the downside to them is that you have to adjust the rockers more frequently then going hydraulic. I'd love to go solid roller on my 388ci, cause as it is, I'm always adjusting my rockers due to my poly locks not locking...lol So yeah, that's my $0.02, good luck and have fun!!! graemlins/thumbsup.gif

I think the carb is a little small, IMO a 750 would be a better match. I have heard the sportman heads are not great out of the box. But with some work they can be made to flow some pretty good numbers. I would consider a basic port job if I were you. If you don't do any head work I would choose the smaller cam. If you decide to port the heads, either cam would work well. Unported heads with the 650 carb 380-400hp. I think 450-475hp is possible with head work, carb and the bigger cam.

How much would head work run me? What should I look into having done?

How beneficial would it be? How would it affect my throttle response, etc.?

Would porting them increase upper range HP while giving up some low end? Or would it help throughout the whole rev range?

Thanks! Keep the opinions coming graemlins/thumbsup.gif