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H-Code to 350HP, Drive Train and Suspension Help
#1
Ok, so I just finished reading months of posts on 351C upgrades and modifications and other schtuff. None seemed to really shoot for what I am looking to find out.

Firstly: Duchess is a 52500 mile 73 H-Code. She is un-restored and in very solid condition. The engine has never been opened (to my knowledge) and is reportedly stock. The only modifications are the Edelbrock performer intake and a 1406 600 carb.

So, I have decided even though the car is very complete and in great condition, a 73 H-Code is not going to sell for any amount that will build another 71-73 to my taste.

Lot's of questions here but I tried to keep them line item.

My vision is a 350 HP build. Something that won't get completely eaten off the line but is easy going enough to be my daily driver. Of course this will be hand-in-hand with a rebuild but what am I looking to do specifically to the engine to achieve this goal?

Should I replace my 2v heads with aussies or edelbrock aluminum or are they good enough for 350?

cams? (I understand what they do but not how to figure out what a better cam is)

pistons, valves? Id like to get good seats so I dont have to worry about unleaded fuel.

I really dont know where to point myself to build this engine up.

Longtube Headers? These are dependent on my choice in heads I believe. 2.5 inch H or X pipe the rest of the way back?

Functional Ram-Air. The idea is just cool to me and why not when I already have hood scoops. Id like to avoid intake/carb combos that will prevent this from becoming reality.

The rear end I'm guessing will be around 3.00 to facilitate highway driving. The FMX is a pretty heavy transmission and Id favor something both lighter and possibly with more than 3 gears. I'd like to be able to still perform at least as good as the FMX. Any suggestions?

I don't know where to replace or install a torque converter or do I need to.

Also, would anyone like to fill me in on the finer points of suspension? Not just the handling aspect but how the car rides and what I can do (kit, replacements, or rebuilds).


Interior and Exterior questions in good time.
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#2
That is alot of questions! haha

Longtube headers tend to have horrible ground clearance. If you have nice roads then this should not be a problem Smile Mine hit constantly.

You dont like the fmx transmission? Alot of people dont give this tranny the credit it deserves. Had one in for yearssss with constant abuse and held up flawlessly.
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#3
Thats some good questions.I want to see what gets posted on this.

[Image: 20r9ylt.jpg]
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#4
Sounds like 350 is a good target. As far as the FMX, I'm no expert, but I've read on several sites that the C4 would handle that much HP and is a lot lighter. I'm sure you will get more input here on that.
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#5
if you want ram-air to work like factory i dont think you can have the aussie heads bc of the intake im going through that as we speak i have an rpm air gap and have been told it won't work untill i modofy the air cleaner housing, i did a full roller cam setup and a lot of other stuff check my garage and see, im in the 500hp range havent dynoed it yet but just ran the numbers through the comp cams camquest program and thats what it said 587 or something its a good program with a lot of options u might want to check that out on the com cam website and its free. the stock cleveland has very decent stock pistons at least mine does, i put 3.70 in my rearend with a detroit locker and moser 31 spline axels. but also put an AOD trans in it ie 4 speeds YAY. so i can run about 1800-2k going 70 on the high way saves on gas any questions on my build feel free to ask


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#6
I've not built any 2V cleveland engines (several 4Vs) but, I have looked into doing so a few times. The Australian closed chamber head flows no better than your open chamber head. The advantage is the closed chamber which reduces the probability of detonation and increases static compression for a given piston. The stock 2V intake port plateaus at about .425-.450 lift. With a 2.08 intake valve, a good valve job and minor "pocket porting" the intake will flow to about .500-.520 lift. Given the parameters you described, the aluminum heads seem to be more than you need and expensive. If a set of Australian heads can be purchased cheap enough they might be worth it for the reason stated above. Either way the stock valves should not be used, they break. Consider changing to an adjustable valve train, roller rockers and .080 wall thickness, hardened, custom length push rods. If you stay with bolt down roller rockers you will like need to get custom push rods as well. Choose a cam with lift numbers slightly larger than Int/Exh flow numbers. Keep static compression at about 9.0-9.25:1. Zero deck the block to further reduce the probability of detonation. Duration of about 220 @.050 and a lobe separation angle of 110. The idea on cam selection is support the engine's flow capabilities, vehicle's intended use, and end up with a Dynamic compression ratio that is compatible with the octane of the fuel being used. I do not think a split lift, split duration cam is needed for the 2V head. If the Ram Air permits try a 1" open spacer. You can use the existing Edelbrock intake if max RPM is about 5400-5700. The Hooker Comps fit well and primary pipe size is not too large. For what your goal is a 2.25" exhaust system is a better choice and creates more choices for tailpipes. I'd use the H pipe rather than X pipe (sound preference). Convertor selection is based on a lot of things (weight, gear, tire diameter, and torque curve) but, I'd guess that something that is similar in stall speed to the 71-73 351CJ convertor (about 2200-2400). I think the best first chassis improvement is weld on subframe connectors, especially convertibles. From there higher durometer rubber bushings, matched anti-roll bars, springs, modified lower control arms, etc. I hope this gives you enough information to help.

Chuck
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#7
What Chuck said X2.

I differ on exhaust; I'm not a fan of headers on a street driven car unless maximum performance is the goal. If you are going to run a full exhaust that is not obnoxiously loud stick with the manifolds. I do not believe headers offer much of an advantage with a street exhaust system. I also like the X pipe for efficiency, it helps smooth out pulses and helps scavenge the cylinders even with a full exhaust system and manifolds.

Jeff T.

Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.

When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.

[Image: 1_12_09_14_10_15_11.png]
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#8
Whats wrong with obnoxiously loud
http://www.youtube.com/watch?v=ScIvclKCi_E
  Reply
#9
Tnfastbk;28749 Wrote:Whats wrong with obnoxiously loud
http://www.youtube.com/watch?v=ScIvclKCi_E

WHAT DID ROY SAY?
  Reply
#10
c9zx;28735 Wrote:I've not built any 2V cleveland engines (several 4Vs) but, I have looked into doing so a few times. The Australian closed chamber head flows no better than your open chamber head. The advantage is the closed chamber which reduces the probability of detonation and increases static compression for a given piston. The stock 2V intake port plateaus at about .425-.450 lift. With a 2.08 intake valve, a good valve job and minor "pocket porting" the intake will flow to about .500-.520 lift. Given the parameters you described, the aluminum heads seem to be more than you need and expensive. If a set of Australian heads can be purchased cheap enough they might be worth it for the reason stated above. Either way the stock valves should not be used, they break. Consider changing to an adjustable valve train, roller rockers and .080 wall thickness, hardened, custom length push rods. If you stay with bolt down roller rockers you will like need to get custom push rods as well. Choose a cam with lift numbers slightly larger than Int/Exh flow numbers. Keep static compression at about 9.0-9.25:1. Zero deck the block to further reduce the probability of detonation. Duration of about 220 @.050 and a lobe separation angle of 110. The idea on cam selection is support the engine's flow capabilities, vehicle's intended use, and end up with a Dynamic compression ratio that is compatible with the octane of the fuel being used. I do not think a split lift, split duration cam is needed for the 2V head. If the Ram Air permits try a 1" open spacer. You can use the existing Edelbrock intake if max RPM is about 5400-5700. The Hooker Comps fit well and primary pipe size is not too large. For what your goal is a 2.25" exhaust system is a better choice and creates more choices for tailpipes. I'd use the H pipe rather than X pipe (sound preference). Convertor selection is based on a lot of things (weight, gear, tire diameter, and torque curve) but, I'd guess that something that is similar in stall speed to the 71-73 351CJ convertor (about 2200-2400). I think the best first chassis improvement is weld on subframe connectors, especially convertibles. From there higher durometer rubber bushings, matched anti-roll bars, springs, modified lower control arms, etc. I hope this gives you enough information to help.

Chuck

wow i should have asked u a lot of questions b4 i built mine.... i did all the legwork on my own now i find theres help.... GREAT INFO
now im about to do pipes on mine... what the bid deal between x and h pipes just sound?


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