Questions about hemi swap

[Bolt-Action]

After reading everything I can about doing a modern hemi swap, Im left with a few questions;
my car is a 67 Sat., so in looking for a donor vehicle for a 5.7 or 6.1, ill need the entire motor, injection-pan, and all wiring, computers etc. (but may need a different pan and relocate the filter, also will need to re flash/program comp)
i can reuse my 727, but will need a SB bell housing, and a flex plate.
Chances are ill get a 5.7 since they are way more plentiful, but what's the HP/TQ diff between the two?
Also, how much does the entire 5.7/6.1 weigh (compared to a 440)
Also, how much aftermarket support is there for the 5.7/6.1?
i know chevy has huge support for the LS and fords coyote seems to be gaining popularity, but how does the 5.7/6.1 compare?
Lastly, realistically, with a Mild build-up, how much HP/TQ can I expect to see from a 5.7/6.1? I know the LS can gain a ton of HP/TQ with just minor mods, how do the 5.7/6.1 compare? Is it as easy to milk HP/TQ out of?
thanks

 

[snakeoil24]

Firsdt thing is this motor is a very advanced Modified Polyspherical Wedge, it is not a real Hemi. Putting that side, it is far more advanced than the LS engine in breathing capability. The size and weight savings over a 440 is more than 200 pounds and at first sight i did not think it would be a success. Since that time Chrysler has added 3 new verisons of cylinder heads and withthe latest coming soon, being the scott head i am really getting very excited. This motor will not produce the torque of a Big block, but easily makes horsepower easier and at a lower cost. To build a decent Street Hemi version 2 crossing the 20K mark. This motor is a dream. So what if it is not a real Hemi it still looks like one on the outside. I would build a 5.7 with the automatic it comes with and be very happy in a street car.

 

[Bolt-Action]

Agreed I'm not hung up on the "hemi" name, I'm really trying to decide whether its the route I want to go.
i was thinking of avoiding the trans so I could bypass the wheel sensors etc.

 

[5.7 hemi]

Ok, let me chime in on this.....

The 5.7 vs. 6.1 all comes down cost and availability. Yes, the 5.7 is more plentiful than the 6.1 and both have a ton of aftermarket support, but it will cost more than a ls1, just because it's Mopar.....gm is a dime a dozen.

Basically your donor should consist of motor, trans, wiring, computer(s), and whatever else you can get.

You didn't say what eng/trans you have currently, so I'll break it down for ya.
Any small block trans will bolt to either engine, period.
Your factory k frame will do just fine with the proper mounts, I'll get to that.

What you need if you want just the engine and using a 727 (small block).
Engine..duh, lol.., computer, spacer for the trans and a converter. This will allow you to use the gen3 in you car with your 727 and your golden....but wait, there's more.

TTI has the headers and mounts that will allow the hemi to bolt in/on your factory k frame. You will need to use either an intank pump or external. Use the Intank pump ( tanksinc.com) it has a built in sump and you can use your factory tank. Also use the 99' and up vette filter/regulator.

The computer can be flashed to get rid of the egr, rear o2's, and drop the auto trans if you use te 727.

Wiring harness, get it!!! This will save time, money, headaches and is plug/play...also has the obd2port so you can use a Diablosport intune/trinity for custom tuning.

Hp wise, the 6.1 is more from the get go than the 5.7 in stock form, 345-380 vs 420 for the 6.1. Those numbers will climb when heads, cam, tuning come into play.

My 5.7 has a factory rating of 345hp, but with headers, and tuning, I'm about 370, but I'm build 5.7 stroked to 392 and will be at over 500 at the wheels when done.

If ya got more questions, just ask, I'll do my best to help ya out.

 

[Bolt-Action]

Thanks very much, just the info I was looking for, my 67 has a 440 currently.
the main appeal to me is, ease of use as a daily driver and of course fuel mileage, weight savings is also a big plus, so its a pretty interesting swap.
Are there any downsides to this swap?

 

[5.7 hemi]

It can get pricey, so ya got do some shopping. Also, you will need a mid sump oil pan with matching pick up tube. Expect to pay 300 bones for a Milodon set up and the aluminum pans will be more, but the aid in cooling the oil.

 

[Bolt-Action]

Some of the reading I've done seems to show that the swap needs a LOT of planning or it will get VERY expensive very quickly,
(obviously the tuner and computer re-flash are going to be pricey but unavoidable)
Also, it seems the 5.7's from the Rams seems to be preferable (?), but what other vehicles can I use as a donor?
Are external parts interchangeable between the 5.7 and 6.1 (vice versa)

 

[5.7 hemi]

You don't necessarily need the computer reflashed, mine is an 05' and I just used it as is. The truck computers are what most people use, me included. I guess you could use a car computer but I would check into that.

Most parts can be swapped between the 2 engines, some good results, some detrimental.

 

[Bolt-Action]

What's a decent price for a 5.7 or 6.1? (Just the complete motor with all wiring computer, harness etc.)

in my search, the prices are all over the place,
I've found them for $1200-$2500 for a 5.7, but anything over $2000 seems high to me (?).
and $5300 for a 6.1, seems WAY high to me(?) guy said he pulled it out of a challenger srt8

 

[5.7 hemi]

That's the going rate for either one.

 

[Bolt-Action]

I feel like I'm armed with info now, I really appreciate the info, I'm sure ill have many more questions lol

 

[5.7 hemi]

No problem, and if ya got more ?'s, just ask.

 

[kb67mopar]

Zack is a wealth of knowledge but don't be afraid to take your time and shop. I have come across a few engines that were just good cores for as low as $300. You could pick one up in the 300-700 range in need of a rebuild and either add new stock parts or get a little bit wilder before the transplant.

The truck layout for the timing cover and accessories is more appealing to me however they are all interchangeable. These engines are pretty versatile and definitely on par with anything GM or Ford has put out recently. The aftermarket has really started to support us finally with these things and has lots available. If you want to carb your hemi you can do that as well as go full aftermarket fuel injection... The sky is the limit if your budget it up there too..

I put my Hemi in my car for less than it would have cost me to do a mild rebuild of a small block. But thats thanks to some savvy shopping and a little of Zack's help too (still thankful for that).

The best part: good fuel economy, big block horsepower, modded small block torque and it weighs less than my 273 did.

 

[5.7 hemi]

Geez, your making me blush, lol!

 

[kb67mopar]

Geez, your making me blush, lol!

Credit where credit is due....

 

[Bolt-Action]

Thanks KB,
That brings up another question actually.
I found a 5.7 on eBay for $400, its basically a short block with heads (and rotating assembly).
My question is; is it more expensive to do it that way?
This motor has no, FI, front cover, accessory drive, no comp, no harness, etc etc.
(Though, I agree its the perfect opportunity to go thru it and give it some "upgrades".)

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[5.7 hemi]

I'll jump in. You can get a timing cover for about 40-70 (truck style), new alt. 120, sanden ac compressor 150, power steering pump 100, car intake, although you will need to make some brackets for the alt. and ac for 150, tb stock 50-150, balancer new 100, 6.1 timing set new 90, I have extra injectors and rails for dirt cheap so you would be good there 85, harness 900-1000, used computer 05' truck 150, belt 25-40. Then of course the cost to go thru the engine, bearings, seals possible machine work.

 

[kb67mopar]

You can find some of that stuff cheaper if you look for people parting out a vehicle as well. I got my alternator for $75 and $25 for my throttle pedal sensor from a guy parting a truck. The throttle pedal sensor (if you want to keep your stock pedal) new is $275 so used is a good bet here.

Just take your time and be patient. The engine I found on craigslist for $300 was complete with timing cover and everything minus accessories. I'd keep my eyes open for a deal more like that to avoid paying for each part individually. Even if the block costs you a couple hundred extra, if it comes with all the covers, intake etc you will be money ahead.

It may take you more time then money to piece this together if you want to do it cheaply...so weigh your options based on that, salvage yards are more expensive but fast...etc.

 

[Uncle Don]

great post. learning a lot about a hemi swap in this thread...
thinking of doing the same thing in my coronet...
maybe I need to start a new thread...
thanks again, good info.