Thread: 53J 3R and 53J 4L

What's the difference. The 3R is off of a u13 det and the 4L is off of a highport motor. Direct swap? Any difference at all?

different compression I'm assuming? I'm wanting to start some headwork on my det and was wanting to work on the 4L head while it's sitting. Looking for some advice on which head to use and what my options are.

exact same head i'm guessing

There is a difference. If im not mistaken the rwd head has spots for the alternator on what would be the left side of the engine in our fwd cars as opposed to the right where it normally is. There are also places for the CAS and what not. Will it work? I don't know but there are differences from the rwd to a highport. Maybe you could have your distributor in the back of the engine bay?

From what I've heard, the DET has sodium filled exhaust valves.


I don't think he's asking about a rwd head

yea, it's not a rwd head, unless i'm very badly mistaken.

is it the de or the det that has the sodium filled valves?

I was planning on new seals, valves, springs, and retainers anyways. Are the sodium filled valves really that much different/better? I mean I know the stems are larger in diameter but I could just get some aftermarket valves for the highport head and should still be better than the sodium filled stock valves correct??

u gotta be more specific lol I dunno why I was thinking rwd. Yea i think the fwd det has the sodium filled valves. You could probably upgrade your current valves for close to the price of a det head if you do the work yourself. Especially if you are doing springs are retainers as well. I have 3 spare DE heads and I'm taking one to the machine shop to have it ported and larger valves added as well as springs and retainers. If you have a head lying around off a block just send it in and have them do everything to it then you wont ever have to build a head again.

haha well i was hoping b14 in the pic, and the u13 in the sig helped...haha

I have both heads, I have both sets of valves, springs and retainers. I've already p n p the highport head and was going to put it onto my det block, are the sodium filled valves really that much better?? Should I just pull the det head and work on it instead?? Or is it worth it to have the highport head drilled to fit the det valves? I'm looking to get around 400whp out of this motor, and it shouldn't have any problems revving with bc2's and s&r's. And speaking of revving, aren't the highport valves going to be lighter without the sodium, or is it the other way around??

bump for some more info.

TBH, there's little difference between the sodium filled valves, and non-sodium filled valves. They just help to keep the heat down on the valves IIRC.

I'd just run standard valves, or if you MUST replace them, go with some supertechs.

Here's some more information:

Sodium filled valves are used when extra cooling is required. The hollow valves contain sodium which melts during engine operation. Valve action causes the sodium to circulate, removing heat from the valve head. The heat travels up the valve stem (3) and is transferred to the cylinder head. Coolant channels in the cylinder head carry the heat away.