360 w/J heads-need help deciding

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73SwingerDart

73SwingerDart

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Hey guys-I have a 73 Dart Swinger with a worn out 318. I dont have the expertise or skills to rebuild my motor myself, so I have been looking for a drop in solution. I would like to buy a crate motor but just too much $$$ right now.Im seriously considering buying this motor from a guy. Please look over the build combo information below and let me know your thoughts or if there are any red flags with this combination. The heads are J heads that he is picking up from machine shop this week. He claims the machinist bill is $1400. He said I can come look at it in its current state and he wil finish reassembling.

"1981 model 5.9L 360. fresh rebuild all pistons cleaned up and cylinders were honed. The motor is a short block right now but I have everything needed to reassemble it. comes with 69' model J heads that have 2.02 valves (which are brand new) motor comes with a gasket set, milidon oil pan, new distributor, .509/294 dur mopar purple bump stick, edelbrock RPM performer intake, mopar performance valve covers, new oil pump, new main and rod bearings and piston rings already installed.

The heads are milled and have a good sized port job already done. I have them at the machine shop right now getting the valve job finished:.

He claims this set up should net around 400-500 HP.
Any comments would be appreciated.
Thanks,
Todd
 
The stock J heads will make 380hp stock and approx 400 - 420hp bowl ported if the heads are well done with good parts. And of course if all other aspects are up to par.
 
are you good friends with this guy or at least know his work through others? if not i wouldn't trust a word he says.
 
No, I do not know this guy.
He is changing directions and bought a 440 car and switching his all over to be a BB car.
Price is $1500 and he is willing to through in a good 904 transmission (which I dont need) and a pair of small block headers he was running for his 69 Dart.
 
Don't mean to sound nit-picky, but there is no such thing as a "'69 J-head"! 1969 had 2931894 X-heads. J-heads came out in 1970 - 3418915. Done right, there is nothing wrong with either one as they have similar ports, but I'd check the actual casting number.

Too much porting may hurt if not done right.

Check which Milodon pan it has. The sump on their 8 quart pans will interfere with many headers. TTI's do fit. Not sure about their 7 quart.

I'd be more comfortable with less than +.060" overbore.

Don't forget you'll need a 360 LA B&M flexplate if it's not internally balanced and you use the 318 or other neutral balanced converter.
 
He claims the machinists bill is $1400, yet he is selling you all that iron for only $1500? Plus throwing in headers and a tranny? What a Good Samaritan!
 
Sounds like quite the deal, find it hard to believe he'll sell all that plus a 904 for that price. I'd be all over that if I was closer. And while your at it, if the heads are off and motor is apart, why not zero deck the block and mill the heads to get compression up. Would think that machine shop he has could do that for you.
 
I dont think its sketchy but be warned, thats a pretty good sized cam and from the sounds of it stock pistons so probably less than 8:1 comp. If you buy it youll likely want to put a much smaller cam in it or swap the pistons out.
 
It may be a decent deal, but without any documentation from the shop, i'd haul it right to my own trusted guy and have everything disassembled and checked for the proper measurements. Nothing worse then installing a engine, getting it all buttoned up and on the road, only to find the compression, bearing clearance, ring gap, valve springs, etc. isn't right.

Also, you need to understand that the .508/.509 purple cam is not the most street friendly cam.......meaning a 3,000ish stall converter and a gear of at least 3.55 would be minimum in my opinion for a mainly street driven car....Yes i know it's one of my least favorite cams, and others have made it work. Just something to think about in the overall picture.
 
sounds like a cheap re-ring shortblock, and will have low compression ratio, likely in the 7.8 or 8.0 to one area, would be a real dog with that cam..
 
Baxter61 said:
I dont think its sketchy but be warned, thats a pretty good sized cam and from the sounds of it stock pistons so probably less than 8:1 comp. If you buy it youll likely want to put a much smaller cam in it or swap the pistons out.
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40 thousandths off the heads and 8:1 comp? An 81 5.9 comes with ADVERTISED 8:1 stock. Realistically speaking it probably had 7.1:1. milled that much would jump to around 10 or 11:1 comp.
 
replicaracer43 said:
sounds like a cheap re-ring shortblock, and will have low compression ratio, likely in the 7.8 or 8.0 to one area, would be a real dog with that cam..
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Moly rings. I THINK it was a "King" branded bearing set? Been awhile. And milled .040 J heads on stock pistons 8:1 comp? I guess I am failing to figure out how 2 people have come up with that ratio?

Dakota
 
bighammer said:
He claims the machinists bill is $1400, yet he is selling you all that iron for only $1500? Plus throwing in headers and a tranny? What a Good Samaritan!
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Over about a year I put $1400 into the heads alone with the cost of the heads plus the machine work I had done.

I only sold it for that cheap so I could get out of the small block stuff since I am going big block and only need ONE project. :burnout:

Not only that, I wanted the motor to go to someone from Oklahoma with a A or B body so later on down the road I might see it on a cruise or something.

Dakota
 
yah fresh ported new rebuilt 2.02 x or j doesnt matter thats 1200.00 minumum tranny 150.00
and a good short still be a 15-2 k set-up fresh motor work meet him at the machine , they should know whats up have them quote you a price to put together have them pull the pan off and take a look
 
dk - so you are the seller then?
It sounds like a re-ring as noted above. If that's the case it would have been lower static compression than 8:1 with the factory original heads. The J heads, even milled, would raise that about 1/2 a point, a tad more if you use the MP thin head gaskets. If the crank was not turned and polished, and the block was not bored, and the pistons are "cleaned up original", it's a ring and bearing repalcement. Not a rebuilt engine. I only say this as a commentary - not a judgement or accusation of misrepresentation. I think the price is fair. However it will not ever make 400hp nevermind 500, especially given that cam, with that set of pistons and a ring and bearing job. Depending on the quality of porting and with a better matched cam it might get to the 360-380hp range but even that is pushing it for that low of a static ratio.
 
Somebody figures he can mill .040 off the heads and gain 4 points of compression? I want some of what hes smoking.........:wack:
 
dkbug said:
40 thousandths off the heads and 8:1 comp? An 81 5.9 comes with ADVERTISED 8:1 stock. Realistically speaking it probably had 7.1:1. milled that much would jump to around 10 or 11:1 comp.
Click to expand...
totally inacurate
 
replicaracer43 said:
Somebody figures he can mill .040 off the heads and gain 4 points of compression? I want some of what hes smoking.........:wack:
Click to expand...

Going off of what I have heard from several other people. Including my machine guy who has seen the same setup before.
 
winstoninwisc said:
yah fresh ported new rebuilt 2.02 x or j doesnt matter thats 1200.00 minumum tranny 150.00
and a good short still be a 15-2 k set-up fresh motor work meet him at the machine , they should know whats up have them quote you a price to put together have them pull the pan off and take a look
Click to expand...

My thoughts exactly. Regardless Todd bought the motor and it is now in the hands of his machine guy going with a different rotating assembly. He is still going to run the cam, intake, and heads.

Thanks for the input ladies.

Dakota
 
Wrong or right, I've always used .006" per cc. A lot depends on the circumference/diameter of the chamber, so a .0005 or .0010 more adjustment higher might work better on a large bores.

I should add that I didn't use those numbers for a build, but more for evaluation purposes. Not a big fan of heavy milling. I'd rather use pistons to get where I want to go. :smile:
 
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