Where do I start to swap my /6 to a V8? Want to do a complete engine rebuild for '72 Scamp

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dgfalk

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So I have a 1972 Plymouth Scamp with a /6 in it, and while it runs and drives great, the thing is a turd. Where I park it I have to drive up a big hill and it struggles to get past 65MPH on the interstate. Since I was a kid I have always wanted to completely rebuild a V8 engine from the block up. I now have all the time, and some money to do it. I have many questions on where to start and what I'd like in the end:

  • A weekend/summer car for cruising around town. Has a decent "muscle" car sound to it. Be able to smoke the tires if I want to.
  • Keep it Mopar. 318 or 360, something else? No power adders, just old school carburetor engine.
  • Whatever engine I choose I want to completely rebuild it to be brand new
  • Price: Want to work on a "cheap" engine since it's my first time. Is $2000 - $3000 a decent budget?
  • Make 300HP or so
  • What transmission?
Any advice to get me started is greatly appreciated. Like I said I have lots of time to do all the research and want to try one of the biggest projects I've ever done. I do have an uncle that has built tons of engines for dirt track racing so I have all his knowledge and tools to help. Just want to get your guys' opinions on Mopar stuff. Thanks
 
V-8 k-member or /6 to v8 conversion kit. might be v8 904 length will fit where yours is, radiator, lots of little things. try to buy a car with a v8 that someone is selling/parting out. depending on your machine shop, 2-3k gone woosh. might want to look here on the magnum install section for a few helpies.
 
better figure at least 7-10K maybe more . do it right the first time or you will be just throwing money away.
rebuilt 360 V8 3-4K
good 8-1/4 or 8-3/4 rear 1-2K
rebuilt V8 904 or 727 with decent convertor 1-2K
exhaust .5-1K
driveshaft,radiator,mounts,misc brackets pulleys,carb,air cleaner linkage etc 1K
 

You might also try to round up someone with a PROPERLY running slant and go for a ride. No slant of that model year should "struggle" to 65 on the freeway. Have you ever evaluated it, AKA compression/ leakdown test, looked at oil consumption, and tuned it up? This is not just throwing a set of plugs at it. Adjust the valves if applicable, new points, condenser, rotor, cap, plug wires and plugs, and evaluate the carb operation. Is the power circuit activating? Does it idle smooth? Vacuum hoses properly connected? Distributor advance, both vacuum and mechanical properly operating? Timing? I would not time it to "stock," but bump it ahead about 5 degrees.

Also if you or a fried can weld/ fabricate, you can modify a slant crossmember to accept a V8

So far as crossmember, if you are going to change to a V8 one, stay away from 67 unless you want to "fix" the one year only idler arm mount, and so a 68-72 K member will give you a "like factory" for 72, but you can also use a 73/ later V8 K which will have the later so called "spool" engine mounts. They will work as well, just depends on the price and availability.

I don't remember anymore, I believe the slant lower radiator hose fitting is on the wrong side. As old as they are, you might want to figure on a new one anyway.

You can NOT use a slant transmission or bell housing (stick) You must have a SB trans (auto) or SB bell (stick)

You will need to deal with exhaust, and have either the correct manifolds or get headers. Same with oil pan. Cars need front sump pans while if you get an engine out of a van/ pickup, that pan will not fit a car. 360LA pans are different than 273/318/340 pans. The rear half moon cutout is smaller on a 360 pan. Also 360LA is weighted (externally balanced) and different than 318/340 so you need a 360 weighted converter or special flex plate (aftermarket) or flywheel (stick) and you must have the proper weighted 360LA front balancer.

Wiring changeover is not too bad. You might have to extend/ modify a few wires.
 
dgfalk said:
  • A weekend/summer car for cruising around town. Has a decent "muscle" car sound to it. Be able to smoke the tires if I want to
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excellent and realistic expectations

dgfalk said:
  • Keep it Mopar. 318 or 360, something else? No power adders, just old school carburetor engine.
Click to expand...
318 and 360 are going to be the more available and affordable options
dgfalk said:
  • Whatever engine I choose I want to completely rebuild it to be brand new
  • Price: Want to work on a "cheap" engine since it's my first time. Is $2000 - $3000 a decent budget?
Click to expand...
these two go hand in hand. if you want to rebuild it entirely from the bottom up, the total number is going to depend on a lot of different factors. one of the main ones is machine work. so starting with a good "core" is important. the less you need in that department (and hard parts-- ie pistons) the better the chance that you can bring it in at that budget.

that being said, 3 is a possibility but not a probability. even the most bucks down magnum swap you're going to be hard pressed to hit that number.

dgfalk said:
  • Make 300HP or so
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300 is an easy ask of a 318 or 360
dgfalk said:
  • What transmission?
Click to expand...
you'll need a 904 or 727
dgfalk said:
Any advice to get me started is greatly appreciated. Like I said I have lots of time to do all the research and want to try one of the biggest projects I've ever done. I do have an uncle that has built tons of engines for dirt track racing so I have all his knowledge and tools to help. Just want to get your guys' opinions on Mopar stuff. Thanks
Click to expand...

buy the *most* complete motor you can. the nickel and time stuff will eat up a TON of cash. best deals are from people doing motor swaps or they built something and are upgrading or sold the car and don't need it any more.

figure on dropping around 3500 to get a motor together including purchase, and that would be something that needs minimal machine work-- like a hot tank, hone, rings & bearings, maybe polish the crank. then you'll drop coin on the heads. have the cam reground and then track down an intake and carb. then you have exhuast manifolds or headers. that's the meat and potatoes of it.

the rest of the swap hinges on all the peripherals: radiator (and hoses!), transmission (and a torque converter! and yoke and cutting the drive shaft possibly), motor mounts, minor mods in the fuel system and wiring, and obviously all the accessories and finally exhaust.

there will be so many trips to the hardware store and orders from summit and mancini and rock...

figure something like 7~10K all in, depending.

the other side of that coin is scouring CL, offer and marketplace and rolling dice on a "runner" pull out that maybe you find 318/904 that somebody yoinked out because they're going big block and you can scoop that for like a smooth G and you shop smart on the rest of the stuff and you get the whole thing together for like 2500 but not rebuilt.
 
If you can find a decent engine that runs my suggestion is to just get the engine in the car. You will have enough of a project to deal with and an engine rebuild is costly.

If you're not used to a big project you could burnout before it's ever on the road.

Tom
 
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If your Scamp has an open 7 1/4 in it I'd say be happy with the slant because finding,buying and building an 8 1/4 rearend for a v8 is going to cost about $4k this year and forget about finding an 8 3/4 for cheap anymore. A shortened Ford 9 inch is cheaper and easier now.
A motorhome, hydraulic, Flat tappet 440 is cheaper to build and easier to find than a rollercam 360/5.9 this year. at least in my area anyway.
You'll have to get a trans ,radiator (The hose is on the wrong side for a v8), driveshaft, conversion mounts are easier to get than a k member these days, headers, dog bone, dropped center, center sump oil pan and pickup anyway so put a 440 in it.
About $5k is realistic for a rebuild with everything new weather it's small or big block.
Just make sure whatever you buy is complete.
I haven't seen a 318,5.2 mag or 360,5.9 Mag for sale locally in about 3 years now unless you buy a whole truck( find a 2 wheel drive 1980-2003 Dodge D150/ Ram for under $4000 and swap everything over to your scamp including the rear end, then salvage the rest of the truck or sell it as a roller) , but do find the occasional Motorhome 440, I saw 3 this year, I bought 2 of them for $200 each both ran and had working trans with them. I missed the third it was sold by the time I saw the ad.
and on top of all that a stock 440 will surpass your 300hp goal with double the torque of a smallblock.
 
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Imo, your "easiest" option might be to find a mid '80s Chrysler Fifth Avenue. They came with 318s, 904, and a LBP 8 1/4 and the car can be found for cheap if you look around for a good deal. Bonus points for having a driveshaft that just needs to get cut to the correct length of your car and not needing a whole new one.
I see them pop up running and complete all the time for varying prices, and I've also seen them in the Junkyard complete with minor body damage
It's a great starting point imo
 
Projectile Dart said:
Imo, your "easiest" option might be to find a mid '80s Chrysler Fifth Avenue. They came with 318s, 904, and a LBP 8 1/4 and the car can be found for cheap if you look around for a good deal. Bonus points for having a driveshaft that just needs to get cut to the correct length of your car and not needing a whole new one.
I see them pop up running and complete all the time for varying prices, and I've also seen them in the Junkyard complete with minor body damage
It's a great starting point imo
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He'd have to check the rear end, some of the 5th avenues had a 7 1/4 rear end as well but an added bonus is the front Disc components will swap right over to the Scamp.
I haven't come across a 5th Ave for sale since I bought one 4 years ago but then again I haven't been searching for one.
 
Deltatech said:
He'd have to check the rear end, some of the 5th avenues had a 7 1/4 rear end as well but an added bonus is the front Disc components will swap right over to the Scamp.
I haven't come across a 5th Ave for sale since I bought one 4 years ago but then again I haven't been searching for one.
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I was not aware of that, all the ones I've encountered in junk yards have all been 8 1/4. You learn something new every day
 
Do 5th' Avenues have the same track as A bodies? Don't they have that newer, weird front suspension, with the crosswise T bars?
 
67Dart273 said:
Do 5th' Avenues have the same track as A bodies? Don't they have that newer, weird front suspension, with the crosswise T bars?
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They do have the cross T bars. The wheel base is 5 inches longer than an a body. The track is the same in the front.
I was told that the disc brake spindles will fit a 70's a body without modification. I haven't confirmed it for myself yet.
 
Good thread! Learned a lot. I'm going to replace the slant in my Dart, that I'm restoring now, with a built 440, after I drive it with the slant for a few years. I'll need to re- cam the the thing. A little too radical. I like the idea of a 4 door sedan sleeper.
 
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