Big Block Conversion $$$

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BigBlockBanjo

BigBlockBanjo
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Well.....I've been sort of looking around for a nice small-block (318/360)...but no luck. But when I went to the local yard to buy some sheet metal, I ran across a BB mopar...(suprise, suprise) You just don't see 'em around here....anyway, I asked him what he wanted for that complete engine(no tranny) and he said $250. =P~ My car has a warm Slant Six which I plan to keep until next winter..but I'm starting to feel the need for more displacement. So...I've read that BB's are mucho more expensive to build and install than SB's....but If I'm replacing all that /6 drivetrain...is it that much higher?? Anyway, $250 sounded like a deal to me......what do ya'll think???
This is budget-build stuff...if I put in a 383 it would be all stock with a mild port job and aftermarket carb & intake. (maybe headers) Opinions? Comments? Advisories? :D
 
A small block would probably be easier but if you`re changing out everything anyway then a big block wouldn`t be such a stretch. If you start making horsepower then upgrades to the rear end ,brakes, suspension, and cooling are mandatory no matter whether you go with a small block or a big block. Schumacher makes a set of engine mounts and headers that`ll help ease a big block in that engine compartment.
 
I know that the numbers have been debated here over and over again. BUT, heres my ACTUAL total for doing a 440/727/8.75. This includes buying the motor, trans, 8.75 suregrip rearend, aluminum radiator/fan, trans cooler, 440 t-bars, sway bar, new shocks front and rear, schumacher spool mounts, disc brake conversion up front, rebooting and bushing the entire front suspension, and Im sure a few other things that Im not thinking of off of the top of my head. Right now Im sitting at $4800 and the only additional expense that I have coming (outside of little odds and ends) is shortening the drive shaft. I did get some really good deals along the way as well as some EXCELLENT advice from the awesome people here to help me out. Just some food for thought as you decide which way to go. Good luck and keep us posted as how you decide to go!!
 
there is no hassle in building a big block a-body. it is so easy today you can flip trhough magazines and order every possible thing you need to do a bolt in conversion. the same as a small block. if you have nothing go all out and be happy you did. it will cost a few bucks more but it wont be a huge difference. you just have to be a smart shopper. big block 727 and a truck dana narrowed to fit. the car will be worth more on resale and you wont be able to wipe the smile off your face. i bought 2 400 727 combos for 400 bucks, and they ran. one ran really good with very low wear and high oil pressure. if you stick with a low deck motor you can use hedman b-e body headers for cheap. they do take some dings though. the headers are the big deal. i have done 2 BB conversions, and my bro and a few friends have small block cars. the only way id keep a sb is if it was a sb car and had everything already. even then ???
 
So...I've read that BB's are mucho more expensive to build and install than SB's...
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thats a load of crap. especially since your starting with a 6 cyl.

the big block is a bolt in swap. biggest decision you will have to make is the headders. you will be surprised how close the two builds will be in price. and on top of that there is nothing like a big block a-body.
 
Hi

You didnt say weather or not the B-Body has the rest of the drive train? if the trans, driveshaft and rear are there you might want to consider checking over the whole shabang!

Your going to need the BB trans, a shorter driveshaft (might as well take one and keep the one you have just in case you need to shorten another lol). Check closely the doner axle... if its a 8.75 grab it with the shock plates and brakes. If need be you can have the axle shortened... you wont be able to have the axles from the B-body shorned as they dont have the meat but MOSER can supply custom bigbolt axles and all the other hardware required. If your on a budget this route may be cheaper than an ACTUAL a-body rear complete. (I just wanted to mention that there has recently been a huge number of cheap Ferd 9" rears here in Ottawa... wonder whats going on?)

Regardless of if you go BB or SB your trans, driveshaft and 7.25 rear has got to go! ...ok technically the 7.25 doesnt have to go but it will very quickly 'go' if you dont change it! LOL

Kernel

PS a 74 or later b-body may have the 9.25 rear as in my Charger but I havent looked into the feasability of sortening these. Prolly not worth the effort as apparently they are not as strong as the 8.75's and not as abundant as the C-body 8.75's.
 
abodyjoe said:
thats a load of crap. especially since your starting with a 6 cyl.

the big block is a bolt in swap. biggest decision you will have to make is the headders. you will be surprised how close the two builds will be in price. and on top of that there is nothing like a big block a-body.
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Joe is for sure 1 of the guys to talk to when you do the BB swap. Hes 1 of the people that walked me through it step by step before I made up my mind. Thanks again Joe!!
 
What makes the swap a whole lot easier, than in the past, is using these guys engine mounts and headers. Know matter what K member ya got they can supply the mounts for whatever engine and don't forget the torque rod. Myself and 3 other gentleman I know have used their products and no complaints so far. http://www.engine-swaps.com/
Other than these you're going to need the subframe connectors with the BB which may not be the case with the SB.
One other thing, if I was going to do the upgrade again I'd latch on to a good 400 block and stroke it to 451 which is what I have in mind for the 400 in my garage.

Terry
 
You really don't need subframe connectors in a hardtop. We never had them on my old 67 GT. Your cost will be directly related to how much fabrication you are willing to do and what kind of deal you can find on parts. But, here's the basis of ANY a-body custom build that I would regardless of the engine choice.

1. Bigger brakes and discs
2. More wheel and tire
3. Bigger torsion bars plus a sway bar, good shocks

After that it's just the drivetrain. High performance requires more than a 7-1/4 rear end, so that's the same small block or big block.

So, now with a mild B-motor you can run iron exhaust manifolds and a stock rebuilt 727. A four speed adds considerable cost whether a small block or big block.

I'll have my Barracuda mechanically done for about $500 (that's after the engine and trans core - I have a good condition 440).
 
Thanks for the input! Yeah....I understand about having to change everything else in the drivetrain...I already have poly-bushings and .920(could be .890?) T-bars. All that was free! (Early "B-day" present while I was away...8) Thanks Dad!!) Either way....they are much better than those stock slant-6 pieces. Unfortunatly....only the engine is there for $250...nothing else. I really hope it's a 383. I've been looking at alot of engine bay pics...and a 383 is just easier to service. :read2: The tranny....I can find one of those. The driveshaft.....that might me a little harder. I have a 9" Ford just sitting in the shop.....?? Possibilities? It didn't cost me anything...I pulled it off an early model Fairlane. Disc brakes are on the list.....I think I'm going to try the Scarebird kit....that's the best bang-4-the-buck I've seen. (beside factory setups). BUT....if I change the rear-end....I would love to go ahead and ditch that SBP shtuff.....hehe. I despise the small selection of wheels, even though Coy's has some seemingly *nice* C-5 wheels for sbp guys. Anyways....I guess I better go buy the engine! Another thing....Is it possible to move the rear-axle back about 1-1/2?? It looks like I could get a lot bigger tire in there...plus fill up that wheel well. And maybe even fix the driveshaft problem at the same time??? I'm trying to stay away from tubs. Thanks for the input.
 
BigBlockBanjo said:
Thanks for the input! Yeah....I understand about having to change everything else in the drivetrain...I already have poly-bushings and .920(could be .890?) T-bars. All that was free! (Early "B-day" present while I was away...8) Thanks Dad!!) Either way....they are much better than those stock slant-6 pieces. Unfortunatly....only the engine is there for $250...nothing else. I really hope it's a 383. I've been looking at alot of engine bay pics...and a 383 is just easier to service. :read2: The tranny....I can find one of those. The driveshaft.....that might me a little harder. I have a 9" Ford just sitting in the shop.....?? Possibilities? It didn't cost me anything...I pulled it off an early model Fairlane. Disc brakes are on the list.....I think I'm going to try the Scarebird kit....that's the best bang-4-the-buck I've seen. (beside factory setups). BUT....if I change the rear-end....I would love to go ahead and ditch that SBP shtuff.....hehe. I despise the small selection of wheels, even though Coy's has some seemingly *nice* C-5 wheels for sbp guys. Anyways....I guess I better go buy the engine! Another thing....Is it possible to move the rear-axle back about 1-1/2?? It looks like I could get a lot bigger tire in there...plus fill up that wheel well. And maybe even fix the driveshaft problem at the same time??? I'm trying to stay away from tubs. Thanks for the input.
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You can move the rear back if you have the room , you just need to move back the springs , maybe there is a front hanger that will accomplish it or mount them inboard and just mount it further back . but make sure the rear isn't going to hit the gas tank.

I wouldn't use the poly bushings on the lower control arm ... 2 cents ...

What's the DRIVESHAFT PROBLEM ??? mount the trans , mount the rear , measure what you need and have it made , it's not rocket science .

What is the car that you found this engine in ? maybe its a 400 ??? same block height as the 383 , more cubes which isn't a bad thing .
 
I wanted BB but heck I had everything for SB and it would have took much $$$ to get the BB in there the right way.
 
Starting from scratch the BB shouldnt cost much more then going small block.
 
Instead of buying that motor, look for a running b body with a bigblock and an 8 3/4. you'll be able to use a ton of the parts. Just look for a rusted out POS.
 
really a c-body with an 8 3/4 is the best donor. they usually have 11" drums out back, certain years the axles are long enough to send them to moser and have them resplined. have the housing narrowed with new perches and you have an a-body big bolt pattern 8 3/4 for dirt cheap.you have the motor, trans and a driveshaft you might be able to have shortened. really are better off going with a big yoke o nthe rear and having a 3 or 3.5" driveshaft made and balanced it will last forever no matter how you beat it.
 
do it!!! i have and im skint<broke> have no mopar knowlege and live in the uk where parts are rare as rocking horse s@@@!!! every time i visit the usa i just want to bring so much back you have all the resourses etc!!! good luck with it man!!! oh, i have no garage,just a drive,a 2 ton trolley jack,2 four ton axle stands,its always pi@@ing it down here im going to out there tomorrow whatever sorting out my shifting/hydralic clutch conversion.if i dont do it it dont get done and i dont get to have some fun.
 
Go for it the only additional cost is the headers everthing else has to be changed anyway .
and you will get MSPM (more smiles per mile)
 
JohnRR said:
You can move the rear back if you have the room , you just need to move back the springs , maybe there is a front hanger that will accomplish it or mount them inboard and just mount it further back . but make sure the rear isn't going to hit the gas tank.

I wouldn't use the poly bushings on the lower control arm ... 2 cents ...

What's the DRIVESHAFT PROBLEM ??? mount the trans , mount the rear , measure what you need and have it made , it's not rocket science .

What is the car that you found this engine in ? maybe its a 400 ??? same block height as the 383 , more cubes which isn't a bad thing .
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Thanks for the info....
The suspension kit came with all poly bushings except the lower ones....(Supposed to not squeek???)

Driveshaft? I was referring to having it shortened.....not really a problem. But if I can adjust things so I can drop one in...that's $$$ that I don't have to spend! (I'm budget build here...not cheap, but budget:happy10:)
The engine isn't in a car..and the car it was in is long gone....
Buying another car is a no-go...they simply don't exist here!!! Unless I can scrounge one out of a yard.....long shot.

It is very possible that it is a 400....I have no idea how to tell the difference in Mopar BB's.
 
..badawg..do you have a 440 in your car pictured?.I have a 65 barracuda 273 car that I'm wanting to put in a 440 with out the fender well cutting,,does schumacher make 440 headers for (64-66) years also?///.just wondering if the earlier A body car 440 conversions are much different..
 
Well...I checked out the engines...yes, there was another one there that he had forgot about (!). Both are 400's. One is only a short block (looks like an older engine)..and the newer one has everything but the intake. $200 for either one....:toothy10: But while I was looking at them..he said "Why don't you put a SB in it?? I have a good one over here..." I checked it out, and its a 75 360, complete minus carb. 80,000 miles on it, and he said he would take $300 for it. :angry7: So.....choices, choices... The BB has alot of potential.....plus it's 40 more cubes. The SB is less weight, and easier to work on. (This IS a street car) My goal is a solid 425 h.p. Hmmm.....?
 
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