First time building a 360, need some advice

[AJ/FormS]

Big Mutha

 

[thesiren74]

Lunatti bracket master2 230 duration .480 lift.

 

[MopaR&D]

To the OP... I did my first engine rebuild 5 years ago and it was also a 360 (I'm 25 btw). To put things in perspective I spent about $2500 all said and done and I have a confirmed-by-time-slips 330-horse (at sea level) engine in my '70 Duster that could push 400 with a cam swap. I used a 1975 LA 360 block that had already been bored .060" I got for $100 (didn't find that out until it was at the machine shop) and did the conversion to run Magnum heads because I really wanted the quench; my goal was to build a max-compression pump-gas engine although to have an overall GOOD street (or even mild race) engine for your Mopar that's not necessary by any means. Stock crank, rods, KB hyper pistons, new bearings+hardware, tanked block etc. (saved money because block didn't need to be bored or decked, only honed). Stock reman'd Magnum heads like mentioned with factory 1.6 rockers, Lunati Voodoo 256/262 adv. duration cam (too small but already had it), Air-Gap intake, Hedman shorty headers, 2.5" duals, 750 cfm Street Demon carb. It's very docile, crazy torque which works well with the 2.94 gears and stock-stall 904 transmission and there's lots of potential power waiting with a proper cam.

If I were to do it all over again but go for an engine build with best performance, longevity, and cost in mind I think I'd just swap an entire 5.9 Magnum. BUT in your case you already have the LA 360. I agree with the others, if you can spend the money on an aftermarket set of heads DO IT, you will be much farther ahead overall. First get the block checked out and figure out what machine work needs to be done. Then take a hard look at how much money you are willing to spend on a rebuild. You will need to spend a "minimum" on certain parts and machine work pretty much regardless of how much power you want. For me personally what I then did was rather than target a specific HP number I did lots of research on what good combinations of parts make for 360s and learned about what parts will make an engine less street-friendly. Most importantly what key parts can be used to get the most power increase for the least amount of money and maintenance, and how far factory stock parts can go before they really need to be upgraded to something aftermarket.

 

[Valiant Warrior]

IMHO..... (Warning, did this get LONG; sorry!)
Refer to posts 7 and 17 for one very good combination to meet the originally stated goals. Start with this sentence below and the rest will fall into place:
"Pistons to make a zero deck,closed chamber heads, and a hi-lift cam around 225*@050. And the baddest heads you can afford."

Speaking to the above: If you can afford them and don't want to mess with porting heads etc., stock Edelbrock Performer AL head will be PLENTY bad enough for the first engine. No porting.. bolt them on and get plenty enough flow to scare you to death at the top end. And with growth potential for the future. Get them on sale from AutoZone online when they run their 15% off, 20% off and 35% off sales.

But you can be easily looking at a $5k engine with all of this....... and there are lower cost and simpler ways to get a ton of grins out of this engine, so that begs the question of budget. I see the original statement of 'money not a big restriction' and then the later statement of 'moderate budget'. I guess we need to know what 'moderate budget' means. 318willrun is pointing at ways to do this more cheaply.

Here is a kind of relationship of different parts so you can start to see how the parts tend to work together, and one thing drives another.
1. Lower gearing and lower stall speed in the TC, and general good street driving, drives to the need for higher low RPM torque. That drives to:
- higher static compression ratio (SCR), and so requires different pistons, or and/or head mods like milling the heads and changing valve head types
- limiting the cam duration to keep dynamic compression ratio (DCR) up to an adequate number to maintain that good low RPM torque in actual operation
- using higher cam lift to make up for the shorter durations and still breathe well at high RPM's
- drives to being more careful with ignition timing
2. Higher cam lifts and higher top end RPM's drive to changes in valve springs (which you WANT to do regardless) and sometimes requires the valve guide bosses on the head to be modified.
- If carried so far, high lift goes eventually into changes in rocker arms (which can get expensive)
- Different rockers generally leads to new pushrods
3. You will want to turn higher RPM's so better head flow is needed.
- You either recondtion and port the present heads and put in bigger valves, or buy new heads with the higher flow built in.
- Bigger flowing heads and headers and intake all work together all across the RPM band, and if not carried to excess, will help all across the RPM band.
- Different heads usually require new pushrods

Smaller things to put on your list:
- New and decent timing chain (not the most expensive), preferably with adjustable timing keyways
- New oil pump (just do it!)
- New water pump perhaps a higher flow type for the bigger engine
- Distributor modified or changed for one with a different advance curve
- Rods PERHAPS reworked for a few hundred $$; depends on how hard you will run it. Perhaps aftermarket rods......
- Some valves are expected to be replaced and new valve guides in the heads if you recondition the present heads. (ASSUME that will be needed.) That's more cost, and such seemingly small things drive the end cost of re-using your heads closer and closer to new heads.
- Head porting work is not a low time consumption proposition, and has the risk of head damage if you slip in the wrong place. Sometimes this plays into the decision to buy new heads... or not to do more yourself, and just have a machine shop recondition the existing heads, put in larger valves and seats, and open the area under the valve seats.
- Lighter pistons and/or rods requires a crank rebalance. So piston and rod selection drives that possible added cost.
- Cooling will likely invoke a larger radiator eventually.
- Putting in a new damper is common; the rubber in the original one is likely rotted/cracked, and that can be dangerous.

For a first engine, there will be a TON of little things to do that require your learning about, and then modding and tuning. It is often wise to limit things that are done to the first build to keep it simple. Things that end up on my list for simple for the first time:
- Buy new heads if you are going for higher HP capacity
- Or just have a shop rework your heads and don't bother with much porting if any to keep your workload down
- Keep the carb to 600-700 cfm initially to make it easier to tune
- Follow all the easy formulas for distributor re-curving and timing; there is TONS of good info in this site about that.
- Find a good machine shop to whom you can turn over things and get good advice. Often easier said than done!
- Spend your effort on little things like timing the cam that can make a very noticeable difference. Also spend time and care in assembly, measuring all sorts of clearances.

FWIW, we did most of the oiling mods listed in the sticky in this sub-forum with a hand drill and drill press. It is not hard, but you have to be very careful. I'd recommend it only if you have work experience with drilling.

Finally: How much engine work experience do you have? I'm not trying to put you on the spot, but most everyone here knows their way around engines, and it is easy for us to say 'do this' and 'do that' without considering it may be someone's first go at all of this with no local support.

Great stuff, thanks for the input! As for experience, I've never gotten much into after market stuff, but I am familiar with the components of the engine and can follow directions pretty well for what that's worth. Thanks for the explanation of relationship between components, very helpful!

 

[Boedighw]

Been doing a lot of research myself. I have spent a lot of time around high dollar builds and having cool stuff (EFI, OD swaps, 4 Links, Ect.)
I drive my car a lot more than those guys because I keep my builds simpler. I agree with the above, purchase the best heads you can afford. This may not be Edelbrocks but simply Craigslist $500 Large Valve J-Heads.
Here is the path I'm currently taking:
72' 360 Long Block and 727 ($200)
Machine Work - 2.02/1.60 Valves and Balancing
Lunati Voodoo Cam 268
Home Port Match
Edelbrock Air Gap
KB107 Pistons
Oil Pan for A-Body
QF Slayer Carb 650cfm
O2 Sensor
2400 rpm Converter
Posi for Rear End
PST Suspension

This is about as low buck as I have found and still budgeting $3-4k.

 

[moper]

In case I missed it - what is your budget figure? Be specific... not "I'd like to..." but rather "I can't go past..."

 

[496 polara]

I recently got through with the 360 build for my truck.I bought a "reman" 360 that had been sitting for a long time(10+yrs)in a warehouse.Got it cheap enough.Pulled it apart and as expected some stuff had to go.
I told my machinist to do it like it was his.
He balanced the spinning assy,honed the block with a torque plate and decked it square.Checked the rings/gap.Replaced the oil pump and timing chain.
I picked out the cam(Old Lunati hyd grind Street Master Hydraulic Flat Tappet Cam - Chrysler 273-360 275/275 - Lunati Power )and found a set of Mopar Performance 308 heads(crate motor heads with smog holes plugged and 2.02 intakes) less than 10 minutes from my work for $300.Low mile takeoffs ready to run.
Topped it off with a port matched edelbrock performer(used and free) and a quick fuel 750 vacuum secondary.
Final compression came in a 8.9-1 and it runs like a raped ape in my 87 Dodge D150.It will go sideways when you hit second gear and I am sure the 3.90 suregrip (ebay purchase used) has something to do with it.

I was set to go magnum heads and spend the money until I found these heads.Arguably the best factory(mopar performance)head available.With the junk reman heads I am sure it would make far less power and be painfully average.

Build a solid short block and get the best set of heads you can afford.All of the other stuff can be upgraded as time and money allow.

 

[Valiant Warrior]

Thanks all yet again, I'm hoping to keep the whole project under $4,500 or so, just to put a number on it.