Porting 454 Truck Heads?

[dsilver101]

Sup-

I've got a 454 in a malibu that started off in a truck- since then its received new valvetrain/ lumpy cam, intake, headers, good carb etc, yet its still got the old truck heads which I know are the weak link in this setup. Due to financial reasons I think it'll be about a few years before I can buy good performance heads- which leads me to my question- Can a guy take these heads and port and polish them into something decent? Will the valves be just too small for it to do any good? I know a guy at work who has port matched/polished his heads with hand tools and I am thinking about doing this too. Thanks-

[MrPbody]

Which heads? There are three or four 454 "truck" heads. Some are decent, some are doorstops. Get the casting number (8 or 9 digit number, cast into the head, usually under the valve cover).
In general, if the head has the larger oval ports (non-fuel injection), you can gain significant amounts with the proper method of porting.
Yes, the valves should be enlarged. By using the 2.190/1.88" valves (factory high performance sizes), you can really wake up the mid-range, and if you're careful about the porting, you won't hurt the low-end enough to notice.
The 454 is a good torque engine. You can move your Malibu quite well with it, without building it go high revs. Make as much power in the mid-range as you can, and you'll be using the "strong suit".

[FortechMini11]

possible casting numbers...

330864 70-81 truck
330895 70-76 Light truck oval port
336765 73-84 truck
336781 73-85 truck
343771 68-85 HD truck
343772 76-84 HD truck oval port
346286 75-87 Light truck
353049 73-76 truck oval port
6272292 71-72 truck oval port
14092359 85-88 truck oval port

[dsilver101]

thnx for the info- I'll check it out, hopefully mine are worth a sh*t. Any good online references for good details about each type of head?

[Robs71Nova]

Originally Posted by FortechMini11

possible casting numbers...
346286 75-87 Light truck

I think thats suppose to be 346236 Which are the "peanut port"" heads that make great power up until 3500-4000 RPMS, but are useless after that. I personally have a set of these I would use as a boat anchor if they weren't so heavy..haha. Also
The two heads with the "781" and "049" as the last three numbers are the better/best oval port heads short of aftermarket because they are "large oval port". 2.19/1.88 valves in these work very well. Basically the only head listed you DONT want are the 346236 casting, because everything else you can work with.

www.Mortec.com and www.nastyz28.com are two sites with some pretty good info.

Rob

[MrPbody]

Let's not deal with "possible", let's encourage him to find out exactly what he has NOW, and go from there...

[dsilver101]

All this talk has got me anxious to find out what I really have, I'm popping the covers off tommorow-

[dsilver101]

Got it - 336781

Found this on Mortec :
336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports , boy am I relieved

I saw an article saying pretty much the same thing- if you want more horsepower go with the 2.19/1.88 valves for better flow.

[Robs71Nova]

Good deal man. With a little bit of money into those heads they can really be made to be beasts on the street. Let us know how everything finally turns out.

Rob