How useful are these supporting-role engine components?

They don't loose pressure to the point where there's damage at normal] operating rpms, but they DO lose pressure, this is bled off around the lifters in their bores. I've seen many Cleveland and 351M/400's that would register "zero" lbs oil pressure at idle and still run fine in normal] applications. I stress the word "normal" for a good reason. If oyu're not going to hotrod or dog on one, and don't mind a zero reading in oil pressure at idle speeds, by all means use the std volume pump. The last 400 I had would still register less than 20 lbs pressure at idle(hot) with a HV pump and a bypass hose from the front to the rear oil pressure port. There's no myth about this, it's a well known fact.

1) Aftermarket, SFI approved harmonic balancer=not needed, but if you are putting on a new balancer anyway it is not a bad investment. as stated summit racing has an inexpensive one


2) Windage tray=help keep oil in the pan and not wrapped around the crank. really only needed if you are going to be turning over 3500 rpm on a sustained basis. not needed for the street.


3) Stud girdle=for the horsepower level you are at you dont need one.


4) High volume water pump or water pumps with impellers=for your application you dont need this. as DH suggested get one from a taxi or police unit.


5) High capacity oil pan=you dont need this for the street, but two extra qts of oil will aid in cooling the engine since the oil will run cooler as it has more time to transfer its heat to the pan. just dont use a chrome pan.


6) High volume oil pump=unless you have large bearing clearances you dont need a high volume pump. in fact they cause problems like twisting oil pump shafts(if you use the stock one and you are a fool if you do), and sheared distributor gears.


7) High performance gaskets=felpro makes a few good lines of gaskets. i like the permatorque line best



as for the argument about the cleveland oil pumps, it is NOT a high volume pump, it is a high pressure pump that is used. the best thing is to use a restrictor kit and a standard pump for the street, and a high pressure pump for the track.

what about guideplates? when do those become advisable?

That's part of the 'fully adjustable valve train". You need those when you install a "much" higher than stock lift cam. Roller rockers, etc...

Guide plates and 7/16 screw in studs for the rockers go with using stud mount full roller rockers.... which is what you want for performance.

AFR 185 and stealth are great choices.
As for the items in question,
1)SFI balancer - Not needed for your application but a new or nice replacement might not be a bad idea depending on the condition of your current one.
2)WIndage Tray - I would suggest one, it isn't expensive and reduces the ammount of oil from splashing up against the crank, also reduces frothing effect.
3)Stud Girdle- not needed and aren't extremely effective anyways other than keeping the caps from walking or if your motor does split, keep it mostly together.
4)High volume waterpump- I would suggest one. Stay away from Milidon, they do not flow enough water at idle which is where you need it. Stuarts or edelbrock would get my vote.
5)High volume oil pan- not needed. May help your cooling but also kills ground clearance. Better off with an oil cooler(adds a little more oil and actively cools it too.
6)High Volume oil pump- not needed on the SBF in your application
7)Headgaskets- Fel-pro replacements will work fine for you but I cannot comment on their higher end but possibly lower grade line. Cometic and Graphite headgaskets seem to do pretty well but I don't have any experience with those.

Good luck with your buid. I have a feeling that you will be over 400hp with your build... at least have 400 effortlessly with a soon to be broken T5. hehe
Kevin

Ha, yeah thats been going through my mind pretty much constantly... should I do the engine build as planned, knowing that I'll be pulling out my T5's corpse at some point thereafter and maybe finish it by May, or do I just wait a little longer, do the job right and replace the T5 with a gforce/astro T5 while the engines out?

Okay the choice shouldn't be that hard but I've been waiting to do this engine build for like 5 years, I don't want to wait another month or two

I think the verdict is that a higher volume water pump (either an aftermarket or a police intercepter version), a windage tray, and a balancer would be good ideas. Anything else I should consider?

NOS

If you get the AFR 185s complete they'll come with guideplates and screw in studs. I bought the Summitt balancer and it looks good but I haven't used it yet.

Just run the T5, chances are you won't have much traction in a light 66 so just watch the hard shifting. T5 can last but use the abuse spareingly. Either way if you do have to do an upgrade to a gforce, all the internals will be replaced anyways. You can also pick up a t5 case for cheap and have that done in the meantime.
Kevin

I was so impressed with Print-O-Seal gaskets back in 1981 that I put a set on a flat-top piston 289, torqued them down and left it for 3 days. Then I removed the heads, swapped the gaskets to the oposite side of the block, reinstalled and torqued the heads and ran the engine for 10,000 miles without a problem. It wasen't util I drove back from Atlanta at close to 100 mph and never less than 80 that they failed.

The only time I've had a problem with the Print O Seal head gaskets is when using aluminum heads on an iron block. I would always get the sweet anti freeze burning smell once the engine warmed up. I'm sold on Cometic MLS gaskets. A little more $, but incredibly tough, reusable and perfect for Aluminum heads on an iron block.

After the Printoseal gasket failures with my Canfield heads, I used the expanded Graphite Felpro 5.0 gaskets coated them with Copper-Kote. These have been on my 331 now for two years. Got the motor up to 250+ degrees the other day (need to install an auto switch in the Comet for that) with no ill effects. I did cool it down before killing the engine though. Coolant is 1 gal antifreeze with the balance tap water.

ok, i can maybe see that with the aluminum heads, but i've never had a single failure using them with iron heads

another one... how useful are aftermarket/HEI distributors? again, most people i talk to say that they're only helpful when you're revving past 6k regularly. wondering if i'd see any benefit vs a stocker... thanks

I would just keep the Distro and update the electronics. It doesn't sound like you are going to be winding out the motor to merrit the cost. At least it's one of those things you can replace later pretty easily if you can justify it.
Kevin

I rev the stock distributors to 6500-7500 all the time. No problems and see no reason to buy a 200-300 dollar replacement.

Duraspark distributor with an MSD box for a cheap upgrade or with a Chrystler iginition box, can't remember which one, for a REALLY cheap upgrade.