I've got a 273 mopar V8 from a 65 dart, and I was wondering if anyone knew what kind of heads would interchange on it. I was told 318 heads would swap in with no problem, but I was wondering about what all of my options were. (318,340,360) Anybody help me out on this? I've heard a hundred different answers and I figured you guys could give me a major consensus view. Thanks.
yeah go to mopars ,read some while i was there ,all heads will fit the angle of the holes arealittle difernet on the 273 for the intake,so you wanna use the 318 or up intake, simple as i am i grew up chevy ,so i never have to ask lol
I hit that link, but I couldn't find anything. I couldn't click on anything to find interchange facts or anything else for that matter. I may be stupid but that just doesn't seem like it should be that hard.
I've never personally dealt with a 273. But, I do know that 340 & 360 heads will fit a 318, so it stands to reason that if 318 heads will fit a 273, then the 340 & 360 heads would also. As far as the concern about intake manifolds goes, I figure if you're going to the trouble of changing the heads, you'll be getting a new manifold for it anyways, so even if the larger displacement manifolds are different, it shouldn't matter. One of the most informative sites I've ever seen on ALL Mopar mills, their histories and their geneology is: www.allpar.com They probably won't come out and directly spell out what heads will swap to the 273, but they will tell you what it evolved from and what it evolved into, and you can make a logical deduction from there... Personally, I wouldn't bother with a 273 when a 318 can be had as cheaply as they can. The 318 is no horsepower giant, either, but the 45 extra cubes has to count for something, and Hot Rod magazine did a cheap junk yard build on one a year or two ago and pule over 400 horsepower out of it. Not to mention the fact that they are super common, easy to get parts for, and damn near bulletproof. If you could onlyt hear the terrible stories of neglect and abuse that 318's have lived through...("ol 55 Plymouth" on the HAMB is guilty of such abuse to his pickup, that just refuses to die...)
ya you can put 318 heads on but trie and find 340 heads they have 202 valves ..318 are only 188 I think that,s all I know about that
Go here, register, post and sit back as the answers come rollin in! http://www.moparstyle.net/forums/ Radman sent ya'!
Man... just knew someone was out there talkin 'bout the abuse on my truck Ive got a 318 with well over 300k un-cared for miles, MAYBE 30 oil changes in it's life... and that's tops. Yet i redline it nearly every day. And pile the miles on it. Actually, nearly 500 miles on it last week, alone. Tragic59 is right... lots of abuse. I'll stand by the all-mighty LA engines, to attest their reliability in even the most uncaring of hands. There's a local guy with a 318, all factory parts (i can get a breakdown, if you want), in his '65 cuda... he's running low 12's, and it's a nice daily driver with decent mileage... so capable of some power. The 273 may have less cubes, but that little sucker can wind for a long time... As for your question... 318 heads will drop right on, as will 340, 360, etc... think all the LA heads do. I had a 273 with 340 heads... cracked a head, and came up with a free set of 318 heads (sorry, dont remeber the casting #'s)... the 318 heads had smaller valves, smaller ports, and a larger chamber- but i swear they made more useable power on the 273 than the 340 heads did with their larger valves, ports, and higher compression... all about port velocity, i guess. There's surely someone on the board that'll know far more than me, on this issue, though... and i'd like to hear- building a new engine to replace my 300k+ mile mill, soon...
Thanks ol 55, that's exactly what I wanted to hear. As for the other replies, I could easily get a 318 or a 360 for it, but how many mopars run on those? A lot. Not many 273's around, and I like that. If no one wants there 273 stuff, you know where I'm at.
Yeah, what about 360 heads, I can get those easy, but no one ever says anything about those. Everyone just talks about 318 and 340 heads. How would 360 heads do? Oh yeah, I have an offenhauser aluminum dual port intake manifold that is supposed to fit all of the small block mopars, just so you know.
Yes, I went to that page, but it didn't say anything about what kind of performance advantage or disadvantage you can get by putting other heads on a 273. I want to know if anyone can tell me if 360 heads would be advantageous or not.
oh well from that point ,i would say you would probally not notice any, since the engine is such a small bore and the amount of air fuel that could be put through it is determined by how big a volume the cylinder is along with the intake choice and carb, a motor of that cube well it is just small,unless you had it hooked up to a dyno i would say seat of pants you wouldnt know the difference
What is the point of putting bigger heads on a motor if that is true? I'm just worried about going too big and losing performance.
ya' gotta watch putting those later heads on the early small bore blocks, possible valve interference with the edge of the bore,and for CERTAIN,you will be shrouding the valves,negating the advantages of the bigger heads. wanna' real sleeper? find you a carbureted 360 engine in the junkyard,and slip it in there. dimensionally the same engine,and there's a company called schumachers i believe,that can hook you up with the mounts,as they changed b-tween the earlier and later LA engines. grab the flex plate and converter from the yard as well,as there may be some balance issues i am not aware of on the 360. it may come with a lock up converter as well(prolly no good for your early 904 or 727),so you will need to research that as well. yes ,you can make that 273 SCREAM,but you will enjoy the torque of a 318 or 360 much more on the street. the 273 wouldn't pull a graesy string from a cats ass! just my take on it. hope this helps. later.
Ok, but I really want to keep my 273. It's fairly fresh and I like that it is not too common. (only made for 5 yrs.) I just want to know what heads will fit on it and will actually do some good towards performance. I have looked at the allpar pages and they say that they will almost all fit, but I was just wondering which ones would give me the best set up. That's the only question I have. Anyone help me out with THAT question?
Swirlport heads from the mid-80's. I believe '85-'86... That's what they used on the junkyard 318 build up that pulled over 400 horse power in that Hot Rod article. I saved the magazine. I'll see if I can find it and give you the exact year range. But I know it was mid-80's and I'm ALMOST positive the heads came off a 318, not a 360, but I could be wrong on that one.
he is right about them swirly head things(from remembering the article),but as i mentioned before,make sure the valves are not gonna' hit the edge of the cylinder. also,i believe the 273's all had adjustable rocker arms(shaft mounted),so research the "swappability"(TM) of the later shafts to the earlier heads and pushrods and lifter heights and all that other things that tend to slow ya' down. good luck! later
Just saw your post...the 273 was introduced in 64 and 65 as the same top end. These earlier heads and intakes had a differenct angle on the intake bolts...they can go on to the LA engines but MUST be used as a set..later models will go back to the earlier but again as a set. The 66 and up 273 had the same configuration as the later LA 318-360 top end. Now for the heads...the standard 2 bbl 273 used 178 intakes and put out 185HP, the four bbl version used these 178 heads and put out 235HP. In 67 the Fromula S came out, it was a bit different, high compression piston, more readical cam plus the heads came with 188 valves and was rated at 275 horses. This unit also sported a chrome air cleaner and special black wrinkle valve covers with finned aluminum plates epoxied to the top and a chrome oil vent. This little 273's surprised a many cars with their performance. If I had a 273 block I would not hesitate in putting it together.
[ QUOTE ] Yeah, what about 360 heads, I can get those easy, but no one ever says anything about those. Everyone just talks about 318 and 340 heads. How would 360 heads do? Oh yeah, I have an offenhauser aluminum dual port intake manifold that is supposed to fit all of the small block mopars, just so you know. [/ QUOTE ] I'll speak to this one without hesitation and add myself to the chorus of fellas singing the praises of the 318/340/360. I had a Ramcharger with over 300k on it before its first rebuild. When I redid the 318 I bored it 30 over and put on a set of mid to late 70's 360 smog heads. They were dirt cheap, had bigger valves but still had the clearance. I had a decent valve job done on them, stuck in the smallest purple shaft (yeah, that always sounded funny to me too) cam and strapped on a Holley dual plenum four barrel manifold with a quadrajunk. Then painted everything but the carb and accessories black. Talk about a sleeper, nobody has ever noticed from looking at it that it's not stock but it pulls and tows great and the 3 chamber Flow keeps it quiet until you're in it. Unless you really want to build the 273 for fun, I might go with a 360 and do something similar. Good luck and have fun, Big Daddy Eric
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