Project Deeds!~ Looking for low buck mods we can do to a set of cast heads and an aftermarket aluminum intake for a 360. We already know the donor 360 is going to need rebuilt. The plan (so far) is to raise the compression to a reasonable level using forged slugs. Camshaft choice right now is up in the air. Most likely something similar to the purple stick .474 or .484 lift. Headers and 2.25" or 2.50" exhaust. Carb CFM size will depend on how well the engine will breathe. MSD billet distributor and an MSD ignition box is a given. So with that information. What do you guys recommend as far as low buck, cast head and intake mods?
Low buck mods for cast heads and such.
- Thread starter NukeSec1
- Start date
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Backtobasics
Well-Known Member
So you get better answers, I suggest you give the overall direction and use of your build.
What kind of car is it going in?
What kind of behavior are you looking for?
What do you define as "Low buck"?
High RPM, race type motor, or low and mid RPM, torque based motor?
This will allow the group to give recommendations based on your overall direction.
In my opinion, a set of Magnum heads from a newer fuel injected engine would be a great starting point. The heads have great velocity right out of the gate, but are somewhat limited in high RPM or high HP builds due to pushrod pinch area. The bowl areas (on the set I worked with) had half-a**ed machining for the bowl area, so there was a lot of area for improvement. A 3 or 5 angle valve job would not run too much, and a gasket match and blend into intake and exhaust would yield some nice results. The exhaust ports are rumored to be good flowing right out of the gate, but I still found a lot of excess material, and flow impedements around the exhaust seats.
Professional Products makes an RPM style intake that works on Magnum or LA heads. Part number 55025 (polished) and 55026 (satin).
What kind of car is it going in?
What kind of behavior are you looking for?
What do you define as "Low buck"?
High RPM, race type motor, or low and mid RPM, torque based motor?
This will allow the group to give recommendations based on your overall direction.
In my opinion, a set of Magnum heads from a newer fuel injected engine would be a great starting point. The heads have great velocity right out of the gate, but are somewhat limited in high RPM or high HP builds due to pushrod pinch area. The bowl areas (on the set I worked with) had half-a**ed machining for the bowl area, so there was a lot of area for improvement. A 3 or 5 angle valve job would not run too much, and a gasket match and blend into intake and exhaust would yield some nice results. The exhaust ports are rumored to be good flowing right out of the gate, but I still found a lot of excess material, and flow impedements around the exhaust seats.
Professional Products makes an RPM style intake that works on Magnum or LA heads. Part number 55025 (polished) and 55026 (satin).
Hummmmmm, good idea if a head swap is OK with the wallet. Otherwise, sticking with the heads you have now;
Mill the heads to the ratio/cc amount needed. Back cut the valves and do a comp. seat cutting. This will increase the flow in the low lift area. If your limited to valve lift, this is the best area to address.
On the intake, a simple port matching will do. If the cam has enuff duration and/or lift to warrant a single plane but you only have a dual plane, you can cut down the plenum divider and round off the edges inside. Use spacers to lift the carb up high enuff so that the buterflies are just above the top of the intakes carb pad. Style of spacer dependent of style of carb, which leeds me to.....carbs.
On carbs, what ever carb you like, use. On the cheap, a T-Q rebuilt by you is about as cheap as it gets. Holleys are also dirt cheap at swap meets, but the spreadbore T-Q is an excellent street strip carb. Use AFB/AVS rods bent (approx. 3/4 iinch) and cut down to tune the T-Q better.
Mill the heads to the ratio/cc amount needed. Back cut the valves and do a comp. seat cutting. This will increase the flow in the low lift area. If your limited to valve lift, this is the best area to address.
On the intake, a simple port matching will do. If the cam has enuff duration and/or lift to warrant a single plane but you only have a dual plane, you can cut down the plenum divider and round off the edges inside. Use spacers to lift the carb up high enuff so that the buterflies are just above the top of the intakes carb pad. Style of spacer dependent of style of carb, which leeds me to.....carbs.
On carbs, what ever carb you like, use. On the cheap, a T-Q rebuilt by you is about as cheap as it gets. Holleys are also dirt cheap at swap meets, but the spreadbore T-Q is an excellent street strip carb. Use AFB/AVS rods bent (approx. 3/4 iinch) and cut down to tune the T-Q better.
This 360 will be going into a '73 Duster. We are looking for aggressive street performance and some occassional (if not frequent) trips to the track. "Low Buck"....... C'Mon Backtobasics......Your profile name says it all. BACK TO THE BASICS! The basics of scrounging every ounce of HP out of what you have to work with. And a Magnum head swap is out of my sons price range. Think Olds School performance tricks. We are expecting to spin this 360 up to around 6200 RPM Max. I'm more in line with what rumblefish360 is saying. Milling the heads down a bit. Forged slugs, a "tiny" shot of Nitrous could be a possible in the future. I am also inline with rumblefish360 on his carb advice. Our engine tuner is all about a Holley for whatever setup we go with. (He's a Holley Lover), but we will go with what works best on the engine dyno. And we have an engine Dyno at our disposal.
mshred
The Green Manalishi
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i think the cam choice will be a damper on performance especially if you want to rev that thing and make some power. I'd go with something more in the .500" lift range if you plan on these head modifications (thats just me though), as those old purple shaft grinds are archaic...there are much better cams out there nowadays so i'd look around first
good luck and have fun!
good luck and have fun!
bigdemo1
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There's always manual steering and a 4 blade fan,cheap power.I also have a friend with an industrial sandblasting business and we ported my exhaust manifolds one day,just hooked up the hose to the exhaust flange and went for lunch,diets work real well,get rid of extras and start drilling everything else.Single horn,no sound deadener,loose the radio and speakers,no windshield washer jug,smaller steering wheel, lighter buckets,You can drop 300lbs pretty quick.
Nuke;
Help us with what you have now.
What intake is that you have? Is there a time/bracket you want to run in or just create a sleeper street terror?
What gear ratio do you have or will end up with and is a converter change out of the question?
Help us with what you have now.
What intake is that you have? Is there a time/bracket you want to run in or just create a sleeper street terror?
What gear ratio do you have or will end up with and is a converter change out of the question?
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