If Edelbrock would have left Carters original design alone instead of trying to build a better more universal mouse trap we all would have been better off.
Choices choices choices, I had a double pumper once so I’m familiar with the not great fuel economy however I liked it when I stomped the loud peddle, I’ve never had a thermo quad but have had Quadra jets and liked them, I’m leaning more toward a radical street car vs daily driver. I think the problem with a thermo quad is finding a manifold, can buy a air gab clone for less than two hundred but have to run a square bore or I could use a LA manifold and drill the heads many options Thanks guys Dan
Yeah, if it's not a super crazy build, this is what everyone says is the way to go. https://transgo.com/
No problem for a 904 to handle 500. Mine handled well over 520lb of torque, multiplied by a 3800stall converter, and the 2.76 first gear forcing it to push 3800lbs of car with a 3.23 gear hampering it and 28x12.50x15 stickies making sure it didn't spin. I eventually broke the bellhousing off of the case due to extreme chassis flex with no cage or subframe connectors. Internals were still pristine. The 8 3/4 rear axle crosspin had been driven 2inches through the carrier in an attempt to saw it in half with the torque coming in and resistance going out... Make sure the valve body has first band apply and pay attention to not burning out in first unless you immediately shift to 2nd. Also review the Super Sprag or other 16 element sprags. They save your fanny. I firmly recommend a manual valvebody or a Bouchillon Performance throttle valve cable to the carb. I sold my Bouchillon when I went manual valve body, and then that guy sold it again when he went 4 speed. They are the dogs bollocks. Dont waste your time with the Lokar getup. -rick
The Performer RPM with a one inch spacer will equal the performance of the Airgap for less money are easily found used. LA heads I have always left the OEM carbs for the restoration guys plus the fuel boiling that the AFB and others do would wouldn’t work for me. If a Holley is what you’re familiar with a small DP would be fun, gas mileage is controlled by your rt foot. The one exception to the rule is the TQ, it’s hard to beat a properly set up TQ if for no other reason than to hear the knuckle heads tell you how much of a pos it is.
I'm running a ThermoQuad on a 351W using an Edelbrock Performer RPM intake with a spreadbore adapter. Instead of just bolting it on and going with it, I opened up the intake and adapter so there is no restriction and little metal in the way of flow. It works nicely and the 'moan' of the secondaries opening up sounds good. I am running an 800 cfm TQ from a '74 400 Federal (no emissions) that I've rejetted for this engine. I've owned a couple of Barracudas and have always liked Carter carbs so this is a nod to that on this engine.
If you re-drill the magnum heads you can use any intake. As they are your choice is limited. While you're junkyard scrounging , try and grab a A518 or the A500 / 44RE trans [A 500 is the A904 o/d version, and the A518 is the 727 o/d version] These transmissions are dead simple to have O/D and converter lockup without any need for computers [just a couple of oil pressure switches is needed] With the 0.69 O/D ratio you could swap out the 3.5 gears to 4.88 and still have similar cruising RPM's Or if you're sensible [which none of us are ] , just use a cheap Explorer 8.8 with 3.7 gears and cruise at 2300 rpm @ 75mph
Sensible ha-ha. I’ve been called a lot of things but never that! I believe the OD transmissions won’t clear the torsion bar suspension on the early A Bodies.I might drill the heads for LA style intake manifolds then I could run a thermo quad carburetor. I can see I’m going to have to do a Pro/Con list and probably a Cause/Effect list also, although I’ve crossed the fenderwell header off the list. Thanks Dan
Sounds like they add a lot of heat and if I understand correctly the inner fender adds to structural stability , what’s your opinion? Dan
There are posatives and negatives with running fenderwell headers. I think under hood temps are lower due to more airflow, but removing the inner fender does remove some strength from the front. The structural strength can be restored with a tubing brace from the firewall to the frame rail. Under chassis headers are a total bitch to install on most Mopars. I imagine its even worse on early A bodys.. Fenderwells are super easy to install and remove. Tire selection will also be limited to smallish front runners. If you plan to build your own headers, fenderwells should be much easier to build. My Valiant is a street terror that i race and go cruising in, but wouldnt use it for transportation. This is how I have driven and raced it for the last 24 years.
Cool car, well I’ll erase the scratch out line. I’m not looking to build a daily driver, just a toy, maybe go to the strip a couple three times a year. I JUST LOVE THE BUNDLE OF SNAKES look, if I was practical, sensible, not a hoodlum I wouldn’t be here on this site would I ? Thanks Dan
Then cut away !! The cutting isn't the issue here [any hackjob DIYer can do that] ................ It is the welding skills required after ,that tends to raise the bar. Usually only the "horseshoe collar" part of the brace needs cutting out , and a section of 3/16" flat welded in [you bend it in a ring roller to the profile of the tunnel] and extend it down to cap the ends that are cut off But this does ^^^ stop the floor flexing from the torsional loads at the anchor points. There needs to be a decent x-member that goes under the trans that also acts like a "strong-back" that ties the 2 halves of the brace together. It doesn't really matter if the load bearing member goes under or over the transmission
Sounds like a fairly mild build engine, and although a 650 DP will work, I'd prefer an 1850 600 CFM with vacuum secondaries for this engine. I think you'd be a lot happier with the performance and use. There are some really cheap options for fenderwell headers if you can do some welding. I had a spare pair of Patriot fenderwell headers for "fat fender Chevys" that were for a SBC. A friend was building an early Barracuda with a small block Mopar and I sold him the Patriots cheap. He cut the Chev flanges off and welded Mopar flanges on and they worked great! You can still buy those Fat fender Chevy fenderwell headers all over Ebay for around $175-$200 and that's way less than what you'll find already made for your build.
If you like the idea of running a Quadrajet/Thermoquad carb, take a look at the Street Demon carburetors with the "butterfly" secondaries; spread-bore manifold not required. I don't know why anyone would want 4.88 gears on a regularly street-driven vehicle, even if it has overdrive.
Your combination sounds pretty good overall . I have two 360 powered old cars and one 340 powered old car , all with afb 's , because they don't require any tinkering and are decent on fuel mileage. My 360 magnum in my '38 Plymouth pickup gets 20 mpg and runs cooler than my LA small block cars , I really like the magnum ,it is better in every way . If your going to race the car the holley carb will be quicker everytime , but not as good on fuel mileage or as trouble free on the street. 904 will handle all you can throw at it , I have two friends that I suggested using 904's and they have been trouble free . 3.55 gear is a good choice also , that's what I run in my '64 330 wagon .
Sharpone; You are aware that the 360 is an externally balanced engine....right? That means you'll have to get a torque converter for a 360.....not just any LA engine. (Well, unless you internally balance the engine when you build it.) I didn't notice anywhere a mention about body mods. I might suggest sub frame tie bars to stiffen up that unibody construction. If you can source them, look for front control arms and disc brake parts from a '74-and-up A body. That'll give you 5-on-4.5" pattern for the front, and axles with the same pattern are easily sourced for an 8.75" rear. Just a little bit of my opinions.....Roger
Thanks Roger, the 360s are externally balanced but I thought the flex plate is where the balance is. Thanks for mentioning subframe stiffening might be something I fabricate myself. A few members have talked to me about upgrading the front brakes and control arms sounds like advice I need to listen to for sure. The 9 inch drum brakes sound like they are very inadequate. On a side note you all have any flooding over your way? Thanks Dan
Hmmmmm. You might be right about that. At least you're aware of the external balancing.....not everybody is. That's the point I wanted to get across. Yep.....you probably took out a slant for the LA swap, and you're going to be applying a bit more torque than the 170 or 225 had to offer. I assume you'd like your work to survive for awhile. Makes me wonder how many original Hemi A-bodies got twisted into a pretzel over the decades. Well, if they're in good condition, they do work reasonably well, but they do fade under hard use. That's why a lot of Mopar guys recommend that particular swap. You'll need, at the minimum, the upper control arms, spindles, calipers. rotors and brackets, correct prop valve and master cylinder. But as long as you're there, snag the lower arms too. If it's a V-8 car, you can use the torsion bars as well. Get all that from a salvage yard car, and it gets you a really decent upgrade to dual-pot master and disc brakes. Not really....the Cedar river is up pretty good. Local state park is closed, along with a few riverfront campgrounds, but nothing too serious. I understand some smaller towns down around Des Moines are under water due to some flood levy break. It'll drop in a few days if mama nature doesn't make the sky fall anymore. Roger
The balance weight is on the torque converter, B&M makes a weighted flex plate so you can use a neutral balance torque converter, or you can weld a weight to the torque converter. There are pictures online of the size and placement of the weight.
Sounds like balance can be either TC or flex plate from what @57 Fargo is saying, I bought the car without engine or transmission, if it would’ve had a good slant in it I would’ve stayed with it for the cool factor . Sounds like you going to build a T bucket with a slant six Super COOL. My plan is to get it up and running probably with the original diff and front brakes etc. No crazy driving until I get everything sorted out. Hopefully the rain is done for a while. Dan
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