EQ ch454a Heads
 

i purchase a pair of EQ ch454a bare heads and have them at the machine shop. I'm looking to save some time and heartache and I'd like to give my cylinder head guy a list of changes/ modifications that need to be done so that they work on my motor,

They are going on a HP500 carb motor with Gen6 block and emi thunder exhaust with dry tails. On another post bunch of people chimed in with necessary changes to the oil dipstick hole, and other holes that need to be tapped to another size, can someone who has done these heads for a similar application recently provide a full list of what needs to be changed

head bolts? Holes tapped threaded? Push rods? Etc , stock hp500 valve covers will work? Rocker studs, guide plates?

Trying to save some wasted trips back and forth the the machine shop

Specs are here...

http://www.aamidwest.com/wp-content/uploads/2015/10/Chevy_Cylinder_Head_EQ-CH454A.pdf

I would guess that most parts are the same. You're should measure for proper push rod geometry (the valve
angles are not stock).

Make sure to use the right head gasket for your parts combination.

if you took gen 6 heads off, you probably have 7/16th accessory mount holes and bolts on power steering, water pump, etc. the new heads I would guess have 3/8ths holes. easy job drill and tap the bigger holes. big PITA making 3/8ths brackets fit 7/16th mounting holes if it is the other way.

Biggest thing I can say is check pushrod length and get the correct ones once the heads are on. the rocker studs, guide plates should all be available at your machine shop or have them order them, they can usually get them cheapest.

Just did gen 6 525sc with the eq 454a
yes the dipstick tube bracket needs a hole drilled and tapped 1/4-20
the accessorie bolt holes are 3/8 and need to be drilled and tapped to 7/16-14
the rockers studs are 7/16-14 1.9 inch length. Stock is 3/8" 1.9 length
7/16 guide plates stock is 3/8
stock valve covers fit with stock crane gold rockers and stock locknuts
you must measure pushrods as they are way longer at least in my case.
arp 235-4303 head studs
ngk plugs r5671-8

Great info Thanks Guys

Has anybody used 3/8 bolts with the accessory brackets ?

I thought a long time about saying forget it and just use 3/8 The holes are close to 1/2" in brackets and if you torqued them gud and tight the 3/8 would more than likely hold.
Thats not right so I can't roll like that.

For the few minutes to drill and tap out 4 or 5 holes it doesn't make sense not to do it. Plus, you can leave the other 2 ends at 3/8th in case the heads ever end up on an older block. I mean, what bolts to the back of the heads besides maybe a ground wire? I had opposite issue. Fighting the 3/8 brackets trying to get them to fit on gen 6 heads.