Mirada512
Active Member
Hello everyone my name is Derek and I own a 1982 Dodge Mirada. I am currently building a 512 for it and just getting the driveline underway. Can’t wait to see what this group has!
Hello Everyone!
- Thread starter Mirada512
- Start date
Aspen500
Well-Known Member
Welcome sort of neighbor! I'm in South Rib Mountain, about 50 miles from your area.
Lots of good people on here. One thing we love, photo's
A 512, I assume big block??? If it's anything like the 500" in my Aspen, you will be all smiles, like Duke5A said.
Lots of good people on here. One thing we love, photo's
A 512, I assume big block??? If it's anything like the 500" in my Aspen, you will be all smiles, like Duke5A said.
Mirada512
Active Member
Thank you! Yeah I love the small blocks but nothing compares to a big block. The 440 I have had pretty good ridges so I decided to build a 512. It’ll rip when done!
Mirada512
Active Member
Thank you! Yes a 512 big block (440 base). I’m still trying to figure out what rear end to go with. I already have a 9.25 that needs rebuilding or go get an 8.75. I have lots of photos and I am logging everything to help others with later swaps!Welcome sort of neighbor! I'm in South Rib Mountain, about 50 miles from your area.
Lots of good people on here. One thing we love, photo's
A 512, I assume big block??? If it's anything like the 500" in my Aspen, you will be all smiles, like Duke5A said.
Mirada512
Active Member
Question for you if you don’t mind. Your 500 what heads and headers are you using?Welcome sort of neighbor! I'm in South Rib Mountain, about 50 miles from your area.
Lots of good people on here. One thing we love, photo's
A 512, I assume big block??? If it's anything like the 500" in my Aspen, you will be all smiles, like Duke5A said.
I have a 400 based 512 in my 5A. Edelbrock heads, custom headers and a mild roller cam. Built it as an off idle torque monster.
Untouched Eddie heads are a bottleneck for sure on something this size, but I built it to be mild. Trick Flow are the best all around, but aren't available right now.
My B block was a real tight fit too. Don't know what an RB is going to do.
Untouched Eddie heads are a bottleneck for sure on something this size, but I built it to be mild. Trick Flow are the best all around, but aren't available right now.
My B block was a real tight fit too. Don't know what an RB is going to do.
Mirada512
Active Member
The RB is shorter length wise front to rear from the 318 but width wise I couldn’t tell you the difference I just know they fit. I’ll have machined 452 heads in the 512 cause I can’t find aluminum heads for the life of me right now but it’ll eventually get them. It’ll be a mild build as well.
Oldiron440
Well-Known Member
You can make power with the 452 heads but 915s would be better, either way 2.18/1.81 valves with a little work under them and port matching and your on your way.
Aspen500
Well-Known Member
An RB in an F/M/J is tight, but not THAT tight. They fit amazingly well. I'll admit right side spark plug access is tough though, especially with A/C anyways.
Mirada, I used a kit from 440 Source and with a .030" overbore, ends up at 500. I've got 65 closed chamber 413 heads. Have 440 size valves (Milodon SS) in them with the throats opened up, guides tapered, ports clean up and matched, and PWR SS rockers, etc, etc. The headers are (the now defunct) Schumacher "Tri-Y" ceramic coated. They it like a glove, no modifications needed to anything. Not a clue what hp and torque are other than it's more than adequate, lol. There's only one downside to it, the 8-10 mpg on premium.
Mirada, I used a kit from 440 Source and with a .030" overbore, ends up at 500. I've got 65 closed chamber 413 heads. Have 440 size valves (Milodon SS) in them with the throats opened up, guides tapered, ports clean up and matched, and PWR SS rockers, etc, etc. The headers are (the now defunct) Schumacher "Tri-Y" ceramic coated. They it like a glove, no modifications needed to anything. Not a clue what hp and torque are other than it's more than adequate, lol. There's only one downside to it, the 8-10 mpg on premium.
Mirada512
Active Member
I can’t find 915s or 906s around here but I do have 3 sets of the 452s. I do plan on port matching and doing my own polishing. I’m working with a machine shop to make sure I don’t screw anything up but it’ll be a fun build!
Mirada512
Active Member
I can’t find 915s or 906s around here but I do have 3 sets of the 452s. I do plan on port matching and doing my own polishing. I’m working with a machine shop to make sure I don’t screw anything up but it’ll be a fun build!
I am also using the 440 source 512 kit. I have 452s that I’m working with and the shop I’m working with will help me with those. It sucks that Schumacher went defunct. I was looking at the tri-y headers and can’t find anything close so I’m thinking about fender well headers. I’m expecting that for fuel consumption haha
Mirada512
Active Member
Yes it will be! My dad wants to race when I’m done with it. He thinks I’m building a 318. He has 70 road runner 440+6, he will be shocked for sure lol
Summit is showing Eddies in stock. 84cc head. CHRYSLER Edelbrock 60929 Edelbrock Performer RPM Cylinder Heads | Summit Racing
Those are for flat tappet cams. Same retainers and locks if you needed to swap springs for a roller.
Don't know what you can do regarding headers though. There is a guy on Moparts with a 440 Diplomat with long tubes I think. Don't where he got them. For me I couldn't find anything that would fit, so I caved and had a set made at a local shop out of SS.
Joe12459
Well-Known Member
Sounds like a sweet build!
Mirada512
Active Member
It will be, I’m just waiting on parts now. Talk about snail mail! Luckily I was able to find everything I need. The only thing I’m struggling with is picking a rear gear ratio.
What is the rest of the setup? Cam/converter/weight/usage?
I used to run a 4.10 when I had a 360 and left that ratio in the car for the first year after the 512 swap. It was like driving around on ball bearings. When I changed axles I stepped down to a 3.54 and still spin the tires on a 45MPH roll if I'm not careful.
Mirada512
Active Member
Cam is a .494/.514 with 107 lsa, 2400 converter (recommended by lunati) car will be close to 3600# and mainly street but will get stop light abuse. I was thinking going with 3.55. It came with 3.55 from the factory but the 318 had no power and cruised nicely.
