OK.. After reading many similar posts. I think I am more confused so I thought I would ask this forum for your help and insight. My son Jeff (17) Loves the 70's and Mopars so last year we got him a 72 Duster that he loves.. Little father son project.(maybe more father project) He's learning.. Anyways he has got to drive it all summer but now it's time to refresh this Slant Six.. WHAT DO I DO? I do not want to spend a boat load of money but while it's out I don't want to skimp either (willing to put in a few extra hundred $$) Remember he's 17 and loving it with like 70p.s.i per cylinder. I have picked up a super six carb and manifold from the junk yard that he has been running with. We have also put on new exhaust 2 1/2 off the header pipe then y pipe to have duals out the rear. Engine is leaking oil good from the front crank seal area. I am not sure of the engine. block# is 2806830-7 going to try to post pictures look at the head. What is it from? (No tubes) No history on engine. Should I work with this one or should I look to work with another? Do I bore this block over? Do I rework this head? I would really like to get her to run great on a low budget, It's a automatic # 2B435041 7 1/4 rearend tag reads 276 and 4"small bolt patern. Fire away I am sure I will ramble on.


I am very impressed with this sight. Thanks in advance. Bill

Welcome on the board. The no-plug-tube head started in '75; your block casting number would have been found on a '72 block. So it looks as if the head has been swapped.
Whether to build up this engine or get another depends on whether you can afford to have the car dry-docked (out of commission/not moving) while the engine's being worked on. Before you start in on this or another block, figure out your exact goals for what you mean by "run great" (how fast, how quick, how economical of fuel) and for your budget. Then post your detailed thoughts and you'll get suggestions for how and where to most effectively put your effort, time, and money. The Super Six is a good start.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

The Super Six and 2 1/4" exhaust will really wake up the engine without turning it into a "hot rod", on the off chance that his love-affair with the slant begins to fade a little...

Good luck! Sounds like you have a great project and a smart kid who has "discerning" tastes in cars and engines.

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vm

I would add that the HEAD gives you the most bang for the buck. The head was designed for a 170 ci not the 225ci so put larger valves in and do some home port work and you will see and feel the difference. Also recurving the dist is a great way to get some "cheap" HP.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Thanks for the advise so far guys.
I posted some pictures of the project. hope this link works.

http://slantsix.org/forum/viewtopic.php?t=37456

Looking to run 87 regular unleaded maybe 89 or 93 if it was a good week.

1)What valve size would be recommended?

2)Will it be OK to work with the 75 -UP cyl. head (see picture)

3)Am I loosing anything from not having the tube style head?

4)I am not a engine builder but have rebuilt engines. new bearings/rings valve job the basics (bottle brush hone) ect. & slap it back together.

5)I have completly rebuilt the front end and have a nice set of Craigers on the car (4 " bolt pattern) if I decide not to stay with the same little 7-1/4 rear and go to a 8 3/4 any way of still using these 4 inch bolt pattern wheels. (these mags are to nice not to use)


6) I was told take .100 off the cyl. head?

7)Need to stop the oil leak so I can have my driveway back to normal.

so if I have engine out is it really worth having it bored.30 over and get all new pistons ect. or if my wear is OK do I clean it up,put a new set of bearings and rings rework the head and let it go? (This works for me)

8)Is there a need for a Cam with bigger valves.

9)and what is the talk about longer rods in some engines. Would milling the head give me same results?

Again it will be a daily driver looking for OK fuel economy but at the same time taking advantage while the engine is out. And not burning a big hole in our wallets.

He keeps asking to let hime have my 340 out of my Challenger project but that just ain't going to happen,even if I am in limbo with that car right now

OK, needs to run on regular gas. You'll want to pay careful attention to compression ratio, then. What other criteria do you have for how the car runs?
That really depends on how you want the car to run. It is definitely not necessary/mandatory to install bigger valves; you can make the car run very well — better than stock — without changing the head configuration. On the other hand, if you will be rebuilding the head anyhow, then it probably makes sense to increase valve size. Use the 1.7 and 1.44 inch items from Engnbldr.
Sure. They're a little heavier than the '74-down heads, and spark plug selection is more limited, but other than that no real disadvantage.
OK, well, what exactly are you wanting to do in this case? Get the car running correctly on all six, or hop it up?
The A-body 8¾" rear axle has the same 4" bolt circle as the 7¼" rear axle you have now. Is there anything wrong with the present rear axle?
Just blindly cutting this or that or some other amount off the head is the wrong way to do it, because you have no way of knowing where you started and where you're winding up. You need to CC the combustion chambers — all of them! — and then figure out what kind of cut to take off the head and/or block.
That'll be taken care of in the course of putting the engine back together.
No, don't bore the engine .030" over just to bore it 0.030" over. If it'll clean up with stock bore and pistons, by all means go that way.
I would go the other direction if I were putting an engine back into good shape but not wanting to spend a whackload of money on upgrades: put in a better cam and leave the valves alone.
Not worth discussing on a build such as you seem to have in mind; that's a relatively exotic project that requires new pistons etc.
Then in your shoes, I would forget about different valves. I would put my money and effort into top-grade rebuild components and get a carefully-chosen cam from Erson, and spend time dialing it in so it's timed exactly, precisely right. Use the 2bbl setup you already have with a good, well-tuned carburetor. Upgrade the ignition. If the car's ready for an exhaust system, put in Dutra Duals. You'll wind up with a driveable, reliable car that's a good bit quicker and faster than stock and sounds good, without spending a bunch of money.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

MPGFanatic, and I built a 170 engine, for his 64 Valiant. We bored .060 and honed with a block plate. Stock cast pistons. Cut the deck to get .005 clearence (a 225 will be greater) New moly rings, cam, rod, and main bearings. Had the rotating assy balanced. Cut the head for an honest 9.2 comp ratio. Stock size valves. Mopar performance mildest cam (forget the numbers), stock 1 bbl intake, and exhaust. I think he has a lower restriction muffler. 3 speed on the tree. With a good shifter it could run low 17's in the 1/4 mile, and he is getting about 27 mpg.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Well, I did something similar to what your proposing when I was 18, and got very good results. There are some things you will need to read about and get a good machine shop to do the few things you will need.
1) There is a seller on E-bay that sells oversized valves for the slant six. 1.7/1.44 for around $80 or so to your door. ENGRBLDR
2)OregonCam gives you some re-ground cams for much cheaper than Erson. I had excellent with their 819 model for what your describing. I would suggest advancing it, but go ahead and install it straight up you will still get wonderful results.
3) I WOULD NOT shave the head .100. I would get an online calculator to see how much cc's you need and tell the machinist to give you x amount. My guess would be 50cc I believe. Bronze guides in the valves and 3 angles are nice, last would be stronger springs, but I learned for this build would be somewhere to save some money.
4) The block should be pretty straight forward, I would follow basic bearings and rings techniques.

All in all you got the exhaust and intake taken care off should be a great set-up. I don't know what was written about the 8 3/4 being a 5x4 that is not true in any of my experience.If it was I would have taken the old wheels off the Challenger years ago. They are a 5x4.5 which is the same as the disc break BBP (unfortunately I don't know if all disc setups came with that). But you don't want to do that because than you have different bolt patterns all around.

In the case of a mild street build, I don't think big valves are warrented. They will help with upper RPM breathing, but will have little effect in the street RPM range. There are better places to spend the money.
The "A" body 8 3/4 rears have a 4 inch bolt pattern. All other body (Challenger, etc.) style 8 3/4 rears were 4 1/2

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

What was written (and it is correct) is that A-body 8¾" rear axles have the 4" bolt circle. Non-A-bodies, including the Challenger you seem to be remembering, have the 4½" bolt circle no matter what rear axle they have.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yep! Dan is right I put a 1969, 8 3/4 set up in my 74 Dart Swinger with a 2.76 Auburn posi. There are lots of the 4" bolt circle "A" body axles out there....

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks for all the input.. I like the sound of the elcectronic ignition. Looks like I have a lot more reading to do.

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Well, there you go! Like I said it was my experiences that the bigger rear end had the big bolt pattern. But I'm not the expert

All in all, the rear end will be fine.

What brands would you use?

1)Rings

2)Bearings

3)gaskets



Since I think I am clear on the rears with 4" bolt patterns how about front disk brakes? are the rotors on a 74 dart 4" or 4 1/2" after the engine I think you can see what I may have in mind if the donners are available.

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67-72 A-body disks are the Kelsey Hayes and are 4" or "small bolt pattern"
1973-1976 uses the 4 1/2" bolt circle or "large bolt pattern"...during those same years they still had 9" and 10" SBP drums available...

If shopping around most of the engine rebuild kits use Sealed Power or Fed/Mog parts (melling oil pumps, bearings, etc...)Buying it all in a kit is cheaper than buying everything individually in some cases.


FYI,

-D.Idiot