Mild 460 Build.
 

I'm in the process of building my 86 460 F-250. Currently it's pretty much bone stock besides an emissions delete and some cosmetic stuff. I need to replace my rear main seal over Thanksgiving break and want to tear it down and really look at the engine and replace all gaskets and the the works. My plan is to add:
Hooker 6911HKR headers,
Edelbrock RPM Performer Cam and lifters (https://www.summitracing.com/parts/edl-7167),
roller rockers,
a different intake manifold, (not for sure which one I want yet),
port and or get new heads,
a Holley 750 Carb,
get the block and heads painted, cleaned, and polished.
I also need opinions on Magnaflow mufflers and if I should go singles or dual? I want to dump them right before the rear axle.

A problem I'm running into is that I have two exhaust manifold bolts broke off in my driver side head and who knows what else. Would it be worth attempting to pull those bolts or finding a decent set of heads to port? Also how much would I need to port to get a good flow with that cam and D3VE heads? I'm not real familiar with head and block work but hope to change that.

Thanks, Dillon.

How far do you want to go with this motor ? All the stuff you mention will have minimal gains without raising the stock comp. ratio.

If you aren't going to put pistons in it then that just leaves changing to a smaller chamber head.

For the intake, use a Weiand Stealth manifold, it'll delete your EGR and breathe better all in one. Port match the heads to the manifold for best results. Also, while you have the rockers off, replace the timing set with a double-roller pre-smog one so everything is straight up instead of retarded 8*.
Unless you plan to get into the engine beyond that, a good single exhaust should do. As previously posted, to get the most out of it you need more compression, but you'll have to replace the pistons or heads to do that, either of which probably means a full rebuild to get right. You WILL see gains without it, but you're leaving a lot on the table... good luck either way!

Also, a Performer RPM cam is a bit much for a pickup engine, better to use an RV/towing cam. Also, you will have to rebuild/replace the heads with that cam, WAY too much for stock springs. You would also have to check clearance between the valves and pistons to avoid contact.

Thanks for the Info! I was looking at the Weiand Stealth manifold so I'll go ahead and pic one up. After reading your cam suggestion, I looked at a summit cam (https://www.summitracing.com/parts/s...view/make/ford) and it seems to better suit this build. I also found this (https://www.summitracing.com/parts/e...view/make/ford) timing set. Later on down the road I will probably do more with this engine. Like you said, there is a lot left on the table but I don't want to get crazy with it at the moment.