Edelbrock 427 Heads on a 390 block

[Wreckless Warren]

I plan on using box stock Edelbrock 6007 72cc 427 heads on my 390 P-Code block.  The cam will be a Comp 270S.  Should I anticipate any interference problems with the valves and the 390's 4.05 bore?

The block (now standard bore) is awaiting cleaning, sonic map and mag so I don't know what the overbore will be.  But I want to keep it to a minimum required, I will spec custom pistons from Diamond pistons if required. Thanks. ww

[Wreckless Warren]

BTW the block will have a Scat 4.25 stroker kit. ww

[jayb]

Not sure about that one.  I know that the Edelbrock CJ heads (2.09/1.65 valves) will not pose any problems, but if I recall correctly the Edelbrock 427 heads have the valves spaced farther apart, just like the factory 427 heads, so that may cause an issue.  But you can always relieve the top of the bore if you run into any clearance problems; that's no big deal.

Just for a data point, I've run 2.19/1.71 valves in the Edelbrock CJ heads on a 4.09 bore 390 block, and did not have any clearance issues.

[rcodecj]

As another data point, I'm running 2.2 intake and 1.66 exhaust with Edl cj heads on a standard bore 390.
I think that's about the max with the cj heads and un-notched bore.
So with the 427 heads I think some bore notching would be in order.
No problems, but if I had it to do over again I would have notched the bore for the exhaust to help flow.
Years ago I put cj exh valves in iron heads on a 390 .030 over and mounted the heads on the bare block, you'd be amazed at how close it looks!

[ScotiaFE]

I don't think there is a difference on the valve spacing between the two heads.
If there is Edelbrock is not giving up the difference.

http://www.edelbrock.com/automotive_new/misc/tech_center/install/6000/6007.pdf

That's a small cam for a big engine.

[Wreckless Warren]

When I said "box stock" they are unmodified.  They have about 2K miles on them from a previous engine and have been in the box for 10 years.  They will be freshened up and set up according to the needs of the 270S cam.

Yes that's a small cam but this engine is going back into a 65 Galaxie with a 3.25 gear, close ratio 4-speed and power brakes.  Also this is a frame off resto show car and family heirloom.  It will not see the race track and be trailered for events far away.

After having a 45 year old CJ rod break at the pin and destroy a real CJ block (while crusing at 3K mind you) I was not going to reuse the 390PI rods on this one.  When I did the math on new rods, forged pistons, machining and parts, I was close to the cost of a stroker kit from Barry.  When he put the kits on sale late last year it was a no brainer.

This engine is going to make huge torque down low and will never see over 5200. With this shortblock and head combo topped of with an 8V induction and 427 long cast iron headers it's gonna be a hoot and have plenty of vacuum for the brakes. ww

[rcodecj]

Warren, I think you're going to have a real fun car to drive. I agree, you're going to have lots of low end torque, and with your setup that will be helpful.

[billballinger]

I don't believe they went with the MR spacing, they should be the same. A 2.19 has plenty of room, but I know on a C4AE-G, a 2.19 valve causes a very noisy and turbulent port.   I measured .220 space to a std 4.05 bore on the intake side, but the exhaust is tight, .060.  You might consider a small bore relief over there.  Anyway, my guy has the turbulence and noise on my C4AE's with 2.19's and will be working on them soon.  Just a heads up, you may want to have flowed to make sure they are not turbulent or noisy on your bore size. I would imagine BarryR's 2.2's StageX heads have the right work done.