Can't say I'm sure yet, I haven't picked up the engines, one's outta a 79 van and the other was an 84 F-250, so prolly D3VE's.

I have to stay all natually aspirated, but a blower would be sweet

 

Just to toss in my bit.

Currently porting a set of DOVE heads. The 460 has a large node in the exhaust port and a BUNCH of extra metal in the exhaust. Rule of thumb I have been told is leave the intake alone and clean up the exhaust. I have been around 3 460 engines that were ported and I have to say it is a bit more than a mere 20HP gain.

Get lots of bits and be prepared to spend some "Quality" time in metal shavings.

 

Well since I posted this I have changed my mind to aluminum SCJ's b/c I can pick them up through work at a hell of a deal. But in my free time I will still be making a set of cast irons to put on another engine. I have also found quite a bit of info around the interent on different sites in the mean time, but still not completely confident in doing it myself, port matching no problem, but the whole port I'm afriad of going to deep.

 

CHECK OUT THIS WEB SITE ON PORTING:
http://www.sa-motorsports.com/litera...05.06B_MED.pdf
OR U COULD SEARCH THIS FORUM FOR "351C 2V PORTING"
I GOT ALOT OF INFO ON PEOPLE WHO HAVE DONE IT BEFORE.
THEY SAY FOR STREET APPLICATIONS U JUST NEED TO
CLEAN THEM UP, BUT READ FOR YOURSELVES FOR MORE DETAIL.

 

hi ,i only have experience with older heads, but with only minor port matching and cleanup of the intake port ,BUT MAJOR smoothing and shaping of the exhaust port mostly getting rid of the large bumps and sharp corners. this is worth more than anything simple !!!
get an old head and try, i am in australia and i had nobody to ask several years ago

 

You can also have the CFM flow matched from the heads to the exhaust. I did and a little timing adjustment picked-up an extra 20 HP. They have to drill and weld a bung in the exhaust behind a header. They then plug in a sensor to the bung and monitor the flow during a dyno pull.

 

I started porting my heads a while ago. Depending on what heads you have, all that is needed is to remove the smog bump in the exhaust ports. Don't get crazy, just remove the bump and smooth out the sides and you should be good. Do not go around the valve guide. It does get a little thin there.

 

I am wondering-I have a set of C9VE heads which are ported(grind marks fully thru the ports, ex. bumps gone)-whether properly or not, I do not know. The exhaust valve seats hammered out from propane, and now the ex. valves are flush to the combustion chamber. I pulled the heads due to the engine stalling out(weakened springs, bad valves). The rest of the engine is a D0VE block, stock bore 429, mild cam with a straight up timing chain, I plopped on some D3's onto so it would run.
I don't live close to any machine shops that I know of, should I get the C9's rebuilt, or just sell em and save up for some edelbrock alum. heads-with all new parts and ports which are engineered to flow??
The 429 works ok for now, and did lose considerable power from swapping to lower compression heads. My plan is to rebuild a 460 shortblock, mild cam, straight up timing chain, flat top pistons(10:1 or 11:1 comp.), and some type of cyl. heads. I also have/will use a weind 8012 intake with twin 425 mixers on top, and want to run headers.
Rebuild the C9 heads, or go Aluminum??
The truck is listed in my sig. Any input would be greatly appreciated!

 

Unlike most other production heads from the Big Three, porting the factory iron 460-carb heads can transorm them a la Jeckyl & Hyde. In our customers' D3VE-headed marine engines that we usually do D0VE head swaps (which require a roller rocker valve train upgrade in the process), a 90 hp gain is commonplace. This is with the same shortblock, camshaft, etc., just changing out the heads.

The factoru 460-carb heads have an aweful flowing exahut port that backs up at about 4000 rpm. Unrestricting the exhaust flow does wonders for the high rpm hp numbers. How much this helps a truck at lower rpms depends on the engine combo, but in a base 460 the numbers would be much less than the 90+ hp noted above.

But that's not what matters. What matters is that full port work on the factory iron opens the door WIDE for bigger engines, and bigger cams that lift the valves higher...which is where the improved flow characteristics of the port work really shine.

A couple more points: 1) One usually gets what he pays for when it comes to cylinder head porting so do your homework and don't cheap out (or you're just wasting your money), and, 2) proper portwork on the 460 iron heads is not as second nature as looking into the port and interpreting what you think is obstructing flow; some of those bumps are there for a reason and do not hurt flow. Grinding the wrong area can result in far less than stellar improvement compared to someone who is well experienced with these heads and knows how to make them produce big power.

Paul

 

X2 on what Paul said!!

 

Between a D3VE, DOVE and SCJ ported to the max, stage 3, whatever you wanna call it, at 7500/8000 rpms, bigger valves, somewhere at .700 lift, 13.5:1 compression, what would you expect for gains, everything setup well bottom end, all roller etc, just wondering what each would max at? I know reincarnation claims around 800HP w/ a DOVE, any idea how much less w/ a D3VE or how much more w/ a SCJ?

 

Which SCJ? The old iron, or the new aluminum head? As for the D3'sa obviously they are not going to get the max flow numbers that can be seen with the D0VEs, but if you look close in Scottys tech section, they get close in flow numbers, and also remember what Paul said, it all depends on who does the porting. I poor port job that is maxed out, will never see the max flow numbers that an experienced porter can get. Now for the aluminum SCJs, there is an apples/oranges difference there that takes them into a whole different game.

 

I'm talking all iron here, since that's what we are limited to in the class I plan to run in. As far as porting, I meant done by a "460 head professional" such as Scott or someone, I found a set of SCJ's for $1,400, set of DOVE's (maybe....) with roller setup and such included (minor port work) for $400 (I really hope I can get these) and I have a couple sets of D3VE's laying around, so I'm looking for HP differences to see if it's fesiable to spend the intial amount of money on the head, say free D3VE's compared to bare virgin $1400 SCJ's. If all said and done I only gain 50HP with the SCJ's compared to the D3VE's I'm prolly looking at $2000 (D3VE's) and $3400 (SCJ's).

 

Your best best is to give Scott a call and talk with him. I know he has a few sets of heads already done at different stages for sale over on the 460 site, so he would be the best to answer your bang for the $$ questions.