360 refresh, couple of questions

[Riderjeff]

This should be child’s play for most of you, but I find this place is the best resource for all things FE!

1) What, if any, issues might arise from using a steel .020 shim type head gasket to up the compression a bit?  I will be changing the heads anyway, so wouldn’t that help the little engine?

2) It’s getting a Performer 390 as part of the deal, and I already have a nice C9AF-U 735 carb that Drew built.  Is it too much carb, or would something like a 600 Summit carb be a better fit? (I do like the 4100 style, got one of those too but I just don’t want to struggle to get it tuned properly.)

The 360 is in a ‘65 T-bird that’s otherwise stock and will pretty much stay that way.  (I know it’s gonna be slow, just trying to make it smooth and reliable.)

TIA

[frnkeore]

First thing is that they never put a 360 in a T-bird so, if it's out of a '65 T-Bird, it should be a 390.

I was a mechanic in the '60's when the steel shim was factory and they worked well. The only issue was with a engine that severely over heated and they require a re-torque after a heat cycle. The HP gaskets are even better, as they have a doubled over fire ring on them. Post a picture a we can tell if it's a HP gasket.

Yes, it will help the engine by, reducing the squish by .010 - .020.

If it's a 390, the 735 cfm carb may show a improvement, worth a try.

[My427stang]

I am not a shim gasket fan, Frank is right that more squish usually helps, need to see where you are and where you'll end up though, but the downside is every stocker that comes through here is crooked and wavy, sometimes severe.  If you add surfaces that aren't freshly machined, the shim combo can result in a poor seal compared to a composition gasket (although a standard head gasket can fail too in the same situation).  My advice, old parts, standard head gasket.  Freshly and accurately machined, let it rip.

I am not a Performer 390 fan either, performance isn't much different than stock, but the weight sure makes it easier to drop on!  I'd be hard pressed to not use it if it's the only option.  Better power makers and how much, depends on end use of the engine, gears, tranny, vehicle, etc.

The 735 is a good carb and the fact Drew went through it makes it more likely to work well than any of your other choices, nd is not too big.

As far as general advice.  1 - headers and good duals with a cross over, 2 - recurve the distributor to match use, fuel and engine details, 3 - gear for use and shift improver kit for an automatic, 4 - improved 4 barrel carb and intake (you have a good start).   Those 4 things are the low hanging fruit that make a car fun to drive and reliable, after that you go inside.

[Riderjeff]

Thanks for the responses, to clarify a couple of things:
The PO stuck this ‘71 2-barrel 360 in there, God knows why.  Maybe he just got it free or had it laying around, who knows!  He used the stock 65 exhaust logs, which DON’T match up to the exhaust ports on the C8 heads the 360 had, so now it has a bad exhaust leak and sounds like a beater scrap metal truck… not cool.  I’ve got a nice 390 with C4 heads sitting on a stand, but my tiny garage makes it a challenge to swap the engines.  So, just looking for reasonable options to fix the 360 issues and just drive it.

Heads and an intake would be a lot faster and easier than the full swap.  Are thinner composite head gaskets available?

[My427stang]

Not really, and depending how deep in the hole it may hurt more than help.

Raising compression with quench above .070 or so, could ping worse.  My recommendation to you is if it's a 360, and especially if not going headers, live with it, they aren't that bad.  Get it quiet, make sure you are getting wide open throttle and enjoy the car

[mygasser]

re the manifold misalignment, i had similar issues with a small block mopar and stainless headers. i stupidly didn't check fitment before stabbing the motor so an in situ solution was needed. i made 2 card templates, one of the head ports and another of the header ports. i drew both onto a sheet of 2mm copper sheet and cut my own gaskets making sure both sets of holes were 'covered'. these were fitted with a light smear of silicone sealant both sides and they sealed just fine. the materials thickness ensured it wouldn't blow out as header gaskets would have and being copper they were soft enough to conform to any slight imperfections.
neil.

[Riderjeff]

Thanks Ross, that’s the advice I was looking for. I’ll have a custom curve done on the distributor next month, it ought to run fine.

[frnkeore]

My suggestion would be to just bite the bullet and put that 390 in there.

The CI intakes take a lot just to get them off. I don't but, at 80 lb, a lot of people use a cherry picker just to get them off and on.

[TJ]

Thanks Ross, that’s the advice I was looking for. I’ll have a custom curve done on the distributor next month, it ought to run fine.

I'm a firm believer in the benefits of doing a custom curve though I think that's something the owner/driver of the car has to do themselves. It requires driving, playing with it, doing time trials, etc.  I don't see how someone not driving the car can optimize a curve.  I only mention this to clarify because it sounds like you're having someone do it for you.

[Stangman]

I second the 390. Whatever money you are putting into the 360 put it into the 390. Even a stock rebuild the 390 has to have a good 30-50 horse more.