I've got a 400 small block
412 SBC
1978 509 high nickel 400 small block bored .060 over (2 bolt main)
Oil pan is new, but stock capacity (5 qt I believe). New bolts
Stock crank and caps. Stock main bolts.
High volume (velocity?) oil pump.
Pistons are cast and the motor has stock compression.
All bearings are federal mogual (sp?)
Edelbrock Preformer Cam
Holley Street dominator intake
Holley 750cfm vac secondary carb
Used Permiblack RVT gasketmaker for all the gaskets.

The heads I have on it are 882s They have 1.94i/1.50e valves. They have been ported, I don't know by who, but on the back of the head "Mr. Ed" is stamped. Should I junk these heads and get some used Vortec heads?

What vortec heads are good? I've heard "but avoid casting number 10239906, which has a modified exhaust seat and loses 20 percent of its flow at 0.120-inch". Is that true?
I was told to find casting number 12558062.
Also, what is the difference between 12558062 and the 12558060 that you can buy in the summit catalog?
Thanks.
-Greg

 

Vortecs would be better than what you've got. They may or may not be the best thing you can do. Don't forget, you'll have to replace the intake too; drilling the bolt holes won't get it, because the intake ports are in a different place. All you'd get by drilling is making it bolt on. But that would destroy ALL of the advantage of the heads, from the extreme mismatch at the ports.... if your intake even is tall enough to cover up the ports in the heads.

That ONE magazine article that printed that about the 906 castings, retracted it the next month, and apologized for printing a bunch of total fabrication. It's all BS. Forget that anyone ever made that comment.

Your cam is unbelievably weenie. It's essentially stock. That's another major target area for improvement.

What is the car (weight, tires, converter, gears)? What exhaust is on it? (headers, Y-pipe, cat, muffler, etc.) What do you use it for? (daily driver, hot street, Sat night special, strip only) What are your goals for it (ET, HP, whatever) What's your budget?

 

Nevermind, I don't have that much money to play around with. I was wondering about my cam though too. I think I'm just gonna drop the motor in now, and maybe next year or the following year do something to beef it up. It'll still be much much better than my LG4 305 I had. Thanks!
-Greg

 

you could always post a pic of the chambers of the heads, just to show the port job. I'm kinda curious. If they've been ported by a non complete monkey, then you're probably ok to use them. Save the $1000 or so, for now.

it's a lot easier to swap cams now, if you've got the lifters, then all you'd need to do now, is buy a new cam. Summit cams (not sure if they're any better then what you have), are rediculously cheap.
A comp xe268 is $69 from jegs now. That's a sweet cam, 'specially for that price. It'd be a tad mild for your 400, but it's a heck of a lot better then what you have now.

 

In a recent hot rod mag test a 350 was dynoed with 882 head, then retested after bolting on Vortec heads.
it picked up 80hp and 65 Ft/lbs torque.

That would decrease your et by a full second.

Say your ported 882's are 30hp better than stock. that still leaves a full 50hp improvement over your ported heads.
I have done this exact head swap and verify the performance gain over 882's . the results are well worth the $$$'s. even with the required new vortec intake manifold and valve train mods.
A change to a Comp cams XE274-10 cam would and another 40 to 60hp. its going to feel like you bolted on a blower or NOS compared to what you have now.
906 vortecs are just as good a 062's. A few marine, industrial, propane vortec motors use a differnt heavy duty exhaust seat that restricts flow on some gm prepared 906 vortecs. you're not likely to run into any of these industrial HD heads. 060 is the part number for the assembled GM vortecs. These factory assembled heads need valve train up grades to use with a Comp XE cam. you can buy upgraded version that have all the nesssessary mods or have a machine shop prepare OEM vortecs for high perf use.
it all worth it in the end. Big torque and horsepower improvment over 882's, even ported 882's.
easy mid to low 12's on your 400.

Your compression ratio will increase for 8.5 ish to 9.5 ish.
use 92+ octane gas.
The only people you'll hear criticing a vortec head swap are thoses who haven't done it.......yet....

 

I realize I'm just speculating here, but....I can't imagine anyone boring a 400 .060 over and then buying dished pistons to bring the c/r down to 8.5:1. Are you sure those aren't flattops? I mean, who builds smog motors and then ports the heads? It doesn't make sense.