Jump to content

512 cid C series on Dakota chassis- build thread


Recommended Posts

Some progress today!

Here’s a stitched up pic- the frame side rear bed mounts getting fabricated from 3/16” plate, the rear 1” .120” wall tube bed floor frame with the poly mounts installed, the axle hitting the inner wheel tub (hafta cut tombstones out of those), and the front bed mount area. 

 

In the front I’m going to incorporate a gusseted tower to support the bed mount and also the top of the front leaf spring hangers.

7BFD600F-6FFA-4AAD-AFA0-F9E3F3B51119.jpeg

Link to comment
Share on other sites

Now that the rear of the bed is located and mounted I was able to sit her down on her suspension for the first time with the weight of the driveline and no jackstands or hardwood cribbing. 

 

It is lower than my challenger! It looks really cool just sitting there but I’m not 17 and I want to drive this around. Along with fabricating front bed mounts the short list includes raising the suspension 2 1/2” or 3”.  I’m going kind of cheesy for now- longer shackles rear and coil spring spacers front. At least it’ll be easy. I hate messing with spring compressors though I treat them like I have a loaded flintlock and a marlboro hanging off my lip. 

32B07F08-B4B0-4B34-BB67-A6DA468D703E.jpeg

Link to comment
Share on other sites

Ha! Man it sure is tempting to raise the front wheel arches and C-notch the frame over the axle but 3” is not a practical ride height around me. As it sits now the rear needs to come up a little just to get over the scrub line and that’s with 17” rims! 

 

How low is yours? You have a stock frame with a heated and stretched straight axle and some leafs taken out of the rear iirc?

 

Any trouble turning or scraping?

Link to comment
Share on other sites

The rain cleared up and the sun dried up the scene enough to drag out the welder. I got a good start on the front bed mount pedestals. They are pretty stout and not crazy tall- I’m thinking they won’t need further gusseting once they are welded on top of the frame and into the top flanges of my leaf spring hangers. 

5A9E22AD-7775-4777-962D-8E0041C67192.jpeg

Link to comment
Share on other sites

17 hours ago, Radarsonwheels said:

Ha! Man it sure is tempting to raise the front wheel arches and C-notch the frame over the axle but 3” is not a practical ride height around me. As it sits now the rear needs to come up a little just to get over the scrub line and that’s with 17” rims! 

 

How low is yours? You have a stock frame with a heated and stretched straight axle and some leafs taken out of the rear iirc?

 

Any trouble turning or scraping?

I have a 3" dropped axle and one leaf removed up front. Out back I have 3 leafs removed and WIllys shackles. I did roll all of my fender lips, but dont have any issues rubbing or anything. With the tires included, I have about a 6" drop up front and 4 or 5 out back. I really like it. This is the most up to date photo including the extra weight of the hemi.

102-viva-las-vegas-pickup-truck.jpg

Edited by 59bisquik
  • Like 3
Link to comment
Share on other sites

Man that sits just about perfect! I want my boards to be in that 4-6” range which looks like what you got goin on.

 

I got the longer shackles installed today. I had to re-drill the hangers from 1/2 to 9/16 which is bigger than most hardware stores carry. Luckily I have a bit that’s a 64th over 9/16” which made it easy once I had some 9/16 fine thread grade 8 bolts. 

 

Now I have a clear 1 3/4” of travel before I get into the bumpstop which is conveniently wedge shaped to gradually increase the spring rate before bottoming. Before the axle sat about 1/8” off the rubber!

 

Jumping my 300lbs on the frame it feels good not harsh but I have another trick up my sleeve to counteract the weight of the bed and gas- a set of old load control springs for rear shocks. Basically they are coil springs with collars that clamp onto the shock body. You install them at full extension (tires off the ground), clamp the cups down that hold the spring ends, then settle the suspension back down. Poor man’s coilovers!

 

 

91756842-BA64-4A1E-B533-1D923733FCDC.jpeg

Link to comment
Share on other sites

Whew! The bed floor frame is done along with four polyurethane iso mounts to the frame, inner tub trimming, and reinforcement of the front spring hangers. I got all the raw steel painted just before it rained too which was good timing. The top surface of my floor structure is about 3/8” above the tallest frame and crossmember sections so that the whole thing will only touch the frame thru the poly mounts.

 

Hopefully the resulting unsupported octagon in the middle won’t sag but I won’t be hauling gravel and I think 1” thick ipe wood tied together with metal strips should handle the occasional bicycle or couch. 

C74A4DD1-2896-4496-9992-30A058DEC7A2.jpeg

Link to comment
Share on other sites

Really like this build, however I would be tickled to just have a stock drivetrain that was in the Dak frame.  This gives me incentive to start looking for a Dak to slip under my 46 WC.  Updating or rebuilding the original drivetrain just seems out of reach for what I would end up with.  

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Thanks Dennis!

 

I agree a clean 318 or even stickshift v6 dakota would have been a more practical choice and wouldn’t need any driveline engineering. The problem is that I had a perfect storm of worn out non running 3.9 with a bent bumper and smashed radiator, 400 motor carb to pan for the big block stroker I always wanted to build, and beat half to death C-series that was too far gone to come out ahead restoring. Plus I wanted an ambitious project to keep myself busy and I never dove this deep into building a hotrod. 

 

Today I re-measured for pinion/driveline offset a few times and got 3/4”. I got a hole drilled and dropped the trans mount in there to try it out. Once the trans was attached to the crossmember I roughly set the motor in line and started measuring off a string where the driveshaft will go. 

 

Seems like my first guess was close- the motor and trans are pretty straight but need to come 1/4” back over toward the driver’s side. Not bad for a second mockup and the trans can easily get moved over with a new hole in the Xmember

18E19A7A-1A2D-41D2-BD26-716960BA974C.jpeg

Link to comment
Share on other sites

Here’s the motor sitting closer to where it will go. The passenger side motor mount will be easy. I separated the floor plate from the v6 mount and I can bolt it to the diagonal motor crossmember then finish the mount with plate steel. The driver side mount will be more challenging since the right angle lump on the crossmember will have to get notched to let the oil pan come over that 1/4” with room to shake and torque around. Then that motor mount will be a little more complicated but not too crazy.

BE211802-A047-4E77-8C70-AE5939B9D006.jpeg

Link to comment
Share on other sites

I pulled the motor, moved the trans mount hole over 1/4”, notched the driver’s side crossmember reinforcement, put the motor back in, got it square, and built the passenger side motor mount bracket using an exploded v6 bracket.

 

Now the driver’s side mount can get fabricated. Since the motor and trans are already located by 2 points all I have to worry about is height- getting it level. 

 

I’m pretty happy with where the motor is sitting. There should be room to route the steering and  exhaust but the carburetor looks like it will be tight and I might lose my fresh air vent in the name of a decent size air cleaner. 

BC4B749D-9C96-4120-9BB4-DE18EDCE088A.jpeg

Link to comment
Share on other sites

https://www.holley.com/products/fuel_systems/air_cleaners/parts/64280

 

Expensive but!!

 

Make your own. Seems you can come up with something like this, just an idea.

 

DJ

  • Thanks 1
Link to comment
Share on other sites

Thanks for chiming in fellas- great minds think alike. I saw that dual snorkel intake before- it’s pretty interesting for sure. I was actually planning to try and look it up again so thanks for the link. 

 

I am not an airflow expert but I did stay at a holiday inn one time. From what I understand carbs take in air in a swirl like a toilet flushing so for a 512” motor with a cam I should have like a 3” tall 14” round filter minimum. That ain’t happenin! Not even if I cut out the guts of the stock fresh air scoop.

 

I’m not racing anybody and there are always compromises- like small tube shorty headers with a huge dent in #8!  I’m doing a street build or a ‘torque build’ which just means I will drive mostly in that 2500-4000rpm area.  So I can get away with a little bit of non optimal airflow in the name of aesthetics or packaging but I do want to rev to 5000 or 5500 and have sharp throttle response so I can’t choke the motor out too much.

 

I love the functionality of the giant cone filter feeding a hat, or even ram air or cold air but  I don’t want a modern fuel injection look though so the high tech streetrod pieces are out for me. I would consider pulling air through the fresh air vent if that’s doable but that sounds like a ton of work for not much payoff.

 

In reality the easiest and best idea is probably just to weld up the vent and run a decent size drop base round air cleaner but what’s the fun in that? It would be worth building something if it could come out cool and be cheap too! Maybe some kind of ven diagram figure eight thing that uses two slant 6 snorkle intakes with a custom offset base and a notched back?

 

I’m gonna sleep on it and look around for more inspiration and cheap junkyard donor parts off my shelf.

 

and yes I know in the mockup my float bowls are on backwards ;)

3F83AD08-489D-4A84-ADEA-3EC95A685245.jpeg

Edited by Radarsonwheels
Typo
Link to comment
Share on other sites

Ha! Again great minds think alike!

 

I have one of those on my shelf except it says a different brand name- edelbrock?  the good old fly’s eye triangle air cleaner. I had it on a 408 stroker smallblock. Come to find out even though they’re billed as 1000cfm they kill HP pretty good compared to a normal round filter. They look cool though and I’m sure I wouldn’t notice any restriction at part throttle.

 

I still reached for it first to try after I got the carb wedged on there to mock up. I couldn’t even get the lip over the bowl vent tube- it sticks out the back too far. It is steel though so it might be a good candidate for donor parts or possibly fit with minor clearancing of the vent lever brace.

Link to comment
Share on other sites

Yeah, I had one I put on a 1972 Impala 2 door. I was fresh out of High School, 1st car, and thought it looked pretty cool. The car had a factory 400 SBC, and a Rochester 4bbl and manifold I put on it. for whatever reason the factory sent it out stock with a 2bbl. Go figure!

  • Like 1
Link to comment
Share on other sites

Well I went back and forth about how to handle getting enough clean non turbulent air to my carburetor. I decided to go with the spend money option to make it clean and get it over with. It’s not very vintage hotrod but it’s going to look perfect with the hood closed and protect my investment with clean air. Hopefully the dual 4” intake and filters will be make the interior of the plenum big amd tall enough to keep it less windy in there so I don’t get wierd afr problems. 

7F5EFA36-7F70-4C40-8913-1F3A36478D8B.jpeg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use