What all is needed to put performer r.p.m. heads on a 289

[jb1dsl]

I have a 289 that I was porting the heads on but they need a total rework and they are not worth it. I have a chance to get soem edelbrock rpm's for a good price and need to know what I need to put them on. The are rpm's with 190's, crane gold 1.6 roller rockers, locwire gaskets, 7000 miles. I know hardened pushrods, what else?

 

[10secgoal]

Won't need lockwire gaskets unless the heads are already cut for them. Nuthin' else out of the ordinary. Just a straight head swap. Unless you have an aftermarket cam, you will want to check the piston to valve clearance because of the larger valves in the RPM's

 

[Dark Knight]

Stepped head bolts or spacers, the rpm's come drilled for 1/2in head bolts. Might need the inserts to plug the air pump holes if it's drilled for emissions..

 

[Max Power]

Good idea to replace the lifters as well. Performance springs can collapse old lifters pretty quick.

 

[jb1dsl]

I have new lifters with the edelbrock cam. They are cut for loc-wire gaskets. They already come with the head bushings for the different size head bolts

 

[jb1dsl]

what about the pushrods, what kind do I need?

 

[stangman67]

When I did this swap I was disappointed with the outcome. I had the same heads, minus lockwires, and put them on a rebuilt stock comp. 289. The heads have bigger combustion chambers, and will lower compression. I had to drill 2 steam holes in the block per edelbrock directions. You can use any stock length hardened pushrods. My car always ran kinda piggish, and didnt feel any different with the heads. I also have the rpm package. I fixed the problem with a set of .200 dome forged pistons and a mild rebuild. After that it ran great! Id look into milling the heads and thinner gaskets if possible. It may require milling the intake, but i dont know if its possible to get the size from 60 cc to 53 without creating problems like distributor fitment and what not.

 

[jb1dsl]

where are these holes supposed to be drilled?

 

[jb1dsl]

How much do you mill to drop a cc in the combustion chamber?

 

[jb1dsl]

Can I use stock 89 302 pushrods? what would it take to convert to a roller cam?

 

[iskwezm]

Can I use stock 89 302 pushrods? what would it take to convert to a roller cam?

your block has to have the bolt bosses that hold the lifter spider in the valley.If you dont have it,you have to drill and tap the block to accept it and about $250+ for the cam/lifters

 

[jb1dsl]

I have the spider out of a an 89 5.0, can I use the stock lifters out of the 5.0 motor. They have 40000 miles on them. Is there pics or a website telling you how and where to drill the bolt bosses?

 

[302 coupe]

you cannot use the stock hyd roller lifters from a 5.0. Well, you can, but you'll have to use a crappy reduced base circle retrofit roller cam. Crane makes a link bar roller lifter setup that will work great in non-roller blocks and will allow the use the full range of roller cam grinds. Converting your engine to a roller cam will cost $500-$600 either way you do it, but the only right way to do it (IMO) is with the link bar lifters.

The heads will work great, but you'll need to find a way to make up for the lost compression. I wouldn't pay more than $700 or so for the used heads you described, even with the rocker arms.

 

[jb1dsl]

I am getting them for less than that, What about shaving the heads to make up some of the compression? How much compression will I lose?

 

[302 coupe]

if your 289 had the stock heads on it....they had 54 cc chambers....and the edelbrock heads have 64cc chambers I believe..stock compression on the 289 was, what, 9.3:1. As a rule, 10cc of chamber is worth approx a full point of compression, so I would say that your compression with the edelbrock heads will be around 8.3:1 or so. It can/will vary a little, but you can safely assume that your compression will be in the low 8 range.

 

[jb1dsl]

The edelbrock heads are 60 cc chambers so it would be 6cc bigger, right?

 

[jb1dsl]

So maybe a c.r. around 8.7, before shaving the heads

 

[302 coupe]

yeah, thats probably pretty close. Honestly, I don't think its that big of a deal. There won't be much of a power difference between a 8.7 and 9.5 motor, maybe 10-15 hp. On the other hand, you can have the heads milled some, but not so much that it throws off the intake manifold alignment/etc, and probably get back into the low-mid 9:1 range.

 

[jb1dsl]

someone else on here said shave .035, does that sound about right?

 

[66P51GT]

I had my RPM heads milled .015" and zero decked the block .015 to net .030". My estimate is a reduction of 5cc in the chamber volume.

Milling the heads is about 2/3 as effective as decking the block. This is because part of the head surface that covers the combustion chamber is flat.

On my application, I had to remove the intake valves prior to milling the heads. The intake valves now protrude below the head mounting surface several thousands.

You will definitely need fly cut pistons if using the 2.02" intake valve.