Author Topic: '67 Mustang Convertible Swapping 390 for 427 Stroker  (Read 2197 times)

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jimeast

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'67 Mustang Convertible Swapping 390 for 427 Stroker
« on: August 13, 2017, 11:39:12 AM »
Probably a thread that will last years...

I have a '67 convertible GTA 390.  A/C, P/S, Power disc/drum brakes, Thermactor, C6, Deluxe Interior.  I have not driven in years due to engine trouble, transmission trouble, radiator trouble, brake trouble, steering trouble, suspension trouble etc...  It's a CA car that might be a legitimate 38k mileage car (I have not been able to make a decision one way or another as I dig into it, if I think the mileage is original.  I think it was wrecked in some way and sat for many years, and then put through a restoration of sorts in the early 90's.  Engine is correct date code, but has been out & apart)

At first I was going to freshen up the 390 and stroke it to 445 and use the original heads.  I got a lot of flack for that idea, and got carried away one weekend and purchased a set of Survival Heads from Blair Patrick that he worked over a bit.  Come to find out Blair could have set up the 390 heads the way I imagined for a reasonable price, but the survival heads were already purchased.
 
The block I've decided to use is a late service block side oiler that sat in the Collier's Collection's GT40 for many years before they realized it should have a properly date coded block.  It is in very good shape, hardly used, but some questionable factory machining and assembly work.  I've had it tucked away for 10 years or so. 

The block has just been machined by my local shop and I’m trying to get everything ordered to balance the rotating assembly in the next week or so.

I'm shooting for a 10:1 Comp ratio and a hydraulic roller with fairly low lift that uses factory non-adjustable rockers.  I'd like a Blue Thunder intake with a 735 or 780 carb on it, but I also get a little carried away with the idea of a Blue Thunder 8v with a set of 600s on top

I'm switching the transmission to a toploader, and have many of the parts needed.  It's a long list of parts and I still need more.  I'm using a McLeod RST Clutch and steel flywheel.  I have a new in the box Romac 427 balancer I've had for 10 yrs or so that I'll use.  I was going to use an original 427 balancer, but the shop talked me out of it.  (One less component to send out and get rebuilt)

More to come.


jimeast

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427 Stroker Update on Block: Interesting Issue Found
« Reply #1 on: August 19, 2017, 08:46:51 AM »
The shop has finished the block work.

Bore: .01 over standard
Deck: .01 off both sides
Dura-Bond Cam Bearings

Problem or Issue:  several of the scallops that un-shroud the valves are very long down the bores.  As much as .300"  Blair Patrick is specifying and ordering the pistons, and he mentioned in an email that he has seen this before.  He asked me to re-check the dimensions on the deepest scallop and he'll account for this.  My 390 GT engine that came out of the Mustang shows the top piston ring exactly .300" down from the top, so maybe this will not be such an issue.

« Last Edit: August 19, 2017, 08:53:32 AM by jimeast »

jimeast

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Interesting Note on Cross Bolt Spacers
« Reply #2 on: September 11, 2017, 09:39:40 AM »
I am slowly getting ready for blueprinting/assembly.  Still waiting for the pistons Blair ordered several weeks ago.  (Could be 4 to 5 weeks for delivery from order date, hopefully sooner) More to come over the next several weeks.

I have the block home from the shop and am getting things ready to blueprint.  I was interested in how different the cross bolt spacer thicknesses would be, and surprisingly, all six were identical.  .376 thick.  This block might have been from the last run of service blocks and if the spacers are all showing a good fit when installed, it appears the machining tolerances improved as production matured.  Unless it was just luck that they all dialed in exactly the same