With that budget you should be able to find some higher performance used heads and have them rebuilt then add the right cam and intake and carb.But if not the cam and intake and carb will help.

 

You can build a street engine with peanut heads, but you're giving up a lot. They'll run out of breath by 4400 rpms and seriously limit performance. Switching to some 049 oval port heads will up the torque ang hp for a minimal investment. Grab some 049 heads for $300, a used Performer for oval ports for $80, and the gaskets for $40.

But, if you want to keep the peanuts, use the low end. I wouldn't describe it as ever having "balls" but it will move things efficiently. Keep the stock compression ratio which should be around 8:1. Use a teeny cam; the stock one will work fine, but keep it no more than about 200 degrees intake duration. You need a cam to match the 500-4500 rpm powerband of the heads. Crane makes a pretty nice Powermax 2020 that is 202/210 with a nice lift profile. I think it would work as well as you can expect with those heads. I forget the LSA of that crane cam, but I'd shoot for 110-112. Too much overlap will kill your low end torque in a low compression engine.

A stock stall converter will be fine, in fact preferred. Keep a high rear ratio (low numerically) in the 2.73/2.90/3.08 range depending on your tire height and transmission. That engine will be happy lugging along at highway RPMs in the 1800 range. Make sure you're above the converter's stall speed, but it will just waste gas if you rev it above 2000 or so on the highway.

Then, post your unbelievable big block mileage numbers and make us all jealous

With peanuts and that cam I would vaguely estimate high 200's/ low 300's hp. If you swapped out for 049s or 781s you might be looking at high 300's with the right cam. I built a 454 with 049 heads, a comp 218/224 cam with 110 LSA, 8.5:1 and I was knocking on 400 hp. I estimated it made a realistic 380-390.

 

Thanks for the recommendations Curtis! Where can I get a set of 049 oval port heads? Should I look at my local parts store to see if they have them? Do you have any idea what vehicle may have had these heads? For $300 (a set I hope!) I'd definitely invest in getting improved heads if it gave me better performance.

 

I bought a set off Ebay that were rebuilt and had been used for a short time. I gambled and won. I paid $250 plus about $75 shipping. Of course, a head rebuild can be expensive, so if you pay $200 for a set of beat heads, expect another $350 or so for a complete rebuild/valve job, but good used heads off a running engine with low miles are fine if you know what to look for.

the 049 head was used from 1973 until the mid 90s on darn near everything; cars, light trucks, performance cars. I had a set that came on a 454 in a 73 wagon, and I had a set that came on a 91 suburban. Its like the standard crate motor head on lower-output big blocks.

Most head service shops should have a set or 50 on hand. Its twin is the 781 head. They're similar enough that some shops actually mix and match those two on the same engine. They flow about 239 cfm on the intake and will support a 454 up to 5500 rpms pretty easily.

 

Thanks Curtis. I'll give my local machine shop a call to see if I could snag a pair off them!

:thumbup:

 

I think it was Car Craft mag (this mo issue??) that the peanut ports were done on a mild street motor and made like 600lb/ft TQ. There were about 8 different BBC heads used for this 'shootout'.

 

G'day jrok151,

curtis73 is right. Swap your heads for some 049's or 781's. We've got plenty in Australia so there should be heaps of them in the USA. :thumbup:

I have a pair of 2.06" 049 heads on a 427. All I have done to them is clean up the chambers and ports. Unshrouded the exhaust valves a bit, had a 3 angle valve job and new guides installed. Port matched to a Weiand Dual Plane manifold. They run great. :mwink:

I'm running a fairly healthy old school solid lifter Sig Erson cam (Hi R M1) and would not recommend it for a daily driver. :nono: But I would suggest a dual pattern cam for your application with a 110 or 112 LSA and 200-220 degrees. Something with a bit of lift say .500"-.550" to utilize the 049 heads breathing capacity. Make sure that the cam will work with a stock converter, you'll get better mileage.

You can download a freeware cam program from Comp Cams called CamQuest. It will give you an idea of what they've got and how it works theoretically for your application.

Carby wise I would suggest using a Spreadbore vacuum secondary like an Edelbrock or a rebuilt Carter Thermoquad or even a Q Jet Rochester. This type of carb will give you better mileage. Stay away from square bore Holleys even the vacumm secondary ones, they just chew up the fuel.

Stock manifolds will hold back you HP, even with a dual exhaust. The motor will start choking above 4000 rpm. This may or may not be an issue, but if you want a bit more out of your Big Block you'll need headers.

Headers will help pull another 20+ HP over Stock manifolds. Don't buy big pipe headers, stick to 1-3/4" for primary pipes on a stockish to mild cammed motor. Get Tri-Y's if you can, they are great for torque. Don't buy shorty headers, great for engine swaps where nothing else will fit but not much better than stock manifolds for HP.

Fit an X pipe as close as possible to the collectors even if you use a big single pipe out the back. Some say they are good for another 10HP ?. Don't go any bigger than 2 1/2" for mufflers and twin tail pipes, or 3" for a big single system. Fitting headers and exhaust system yourself is a big job, so you may have to farm some or all of the work out or have another mode of transport for a few days while you get the job done.

You have to think of the complete package, not just cams and manifolds. With your budget you can do it with some canny scrounging and wheelin' and dealin'. Above all have fun with your project and do it a bit at a time. That way you'll get a seat of the pants feel of what gave you the extra HP or mileage gains. And on that note, keep a detailed notebook of everything you do. It may not seem relavent when you make the notes but it could prove very useful for diagnostic purposes later.

Cheers..........Barry. :thumbup:

 

Before you do anything, what is the state of your 454 as it stands now??? I would suggest a compression test, vaccum test and last but not least a "leakdown" test. Don't go throwing your money arround until you are aware of the above... If yah try to start putting more HP/Torque on a possible "wheezer" you could end up being a mite disappointed.
After you do or have the above tests done, then come back on the board with the results and let us go from there...
Make sure all your ideas are well thought out re. exactly whatcha want to do with the car, street only, street and some drag, weekend warrior, car show.
Lot of good reads on Chevelle.com re. peanuts and how ideas are changing re. these heads... They are not as useless as most currently think...

 

That's a great idea. Thanks for the advise opelitis5. It would be a waste of time, money and effort if the motor was not worth investing in. I post the results in the next day or so.