400 heads on 361
 

Easy question.

Will heads off a 400ci motor fit/work on a 361ci motor?

Buddy of mine has set of heads with hardened valve seats for sale. He's pretty sure all of the usual big block heads will interchange.

Thank you

The heads will interchange. But Some motor home and industrial heads have a different water pump set up.

Right on time with the reply!! Have to go over to buddy's house in a couple hours.

From some of the crazy wording I've used on searches, it seems that they are for 100% certain. I have seen where motor homes are different.

Thanks, Gary :)

If theres any question as to what head you have, give us the casting number off the intake runner on top of the head. Then we can tell what time frame it was made, as well as performance potential. Sounds like a 452 head. (Last 3 numbers) Many 400s came with these heads.

Some of the very early engines had a different rocker shaft mount design. Other than that ANY B/ RB head will interchange with the exception of the heavy truck type mentioned above. These are easily discarded by looking for the water pump mounts in the ends of the head.

The combustion chambers on the 400 heads are likely larger open chamber, and will drop your compression some. The big problem I see with a 361 is getting pistons which will be expensive.

Oh yea, thanks 440. I didn't think about the rocker shafts mounting being different! But yea they are. If you need some, Cork, I have extras. Ok

The last 3 numbers on the heads buddy has is 452. Is that from a engine that was made for running regular unleaded fuel?

Don't plan on doing anything with pistons and hope I don't have to. Will I HAVE to have different rocker shafts?

I didn't buy the heads as of yet, but buddy is taking it to another friend of his for cleaning up and machining valves with a 3 angle cut (what ever that is and I think I said it right)

Hang on to those rocker shafts then Gary, just in case!!

Thanks

Edit:
Not absolutely positive, but I'm 99% sure my valve covers only have 4 bolts where as the heads buddy has, have 6. I should only need new valve covers, correct?

The 452 heads have flame hardened combustion chambers and are made for unleaded fuel. So you should be good there. Alot of builders like this head as it can be made to flow quite well. Especially with bigger valves. But should be plenty for a 361 in stock form. The 4 bolt valve covers came with the heads that have the old style rocker shaft mount set up. So you will need 6 bolt valve covers, and rocker shaft set up. I have some came off the 452 heads with bolts and seperators. And some extra chrome valve covers.

You will loose a very small amount of compression. Probably a good thing IF you are using the stock cam...
You could get that back by re surfacing the heads

Crap! Forgot to come back here last night and post the fact that my valve covers ARE 6 bolt and not 4 bolt. Yay, on that part! Should mean I can just slap those 452 heads on and be good to go, huh?

@TVLynn:
Heads are getting resurfaced and valves getting re-cut.

Cork tried to send you a couple of messages, dont think they went thru! PM me your phone # or e mail. I DO have some P/S pumps. Ok

You need to see what your 361 valve train looks like. Then you can tell what you need. Just pull a valve cover, send us a pic of your rocker shaft if not sure.

That's what I was figuring about what might be under the valve covers. I have no means of doing much of anything to my car myself here. Probably wouldn't even know what I was looking at anyway!! Totally mechanically illiterate when it comes to doing anything myself, but I do understand when someone is telling about something.

Exactly why I've mostly never had an older rod, have to always have someone else work on it!

Might be a few days before I can get back with on this one, but I will be back.

Thank you

Easy, two differences in the old heads. I don't know for certain if both differences always apply, IE some heads may have one or both

1--Older heads have 4 bolt vice newer 5 bolt valve covers

2--Older heads do not have the rocker stands CAST into the heads. Easy to tell You look at the rocker shaft, which sits in a "half moon" saddle on the heads. Some of the older heads have a separate rocker stand, the newer heads have this cast right into the head. I do not know if the shafts, rockers, pushrods interchange between old and new heads.

Actually, the newer heads on the big block have 6 bolt valve covers. 4 along the lower part near the ex manifold, and 2 across the upper part near the intake manifold. Older valve covers had 2 below, 2 above. And they leaked alot! Lol

The buddy of mine is pretty sure his heads should work with no issues now that I have told him my valve covers are 6 bolt. When I told him I thought they were 4 bolt, he had doubts, but now is quite positive they wil work without an issue.

I'll let you all know sometime in the near future where I'm at with this. If buddy remembers, he's supposed to be taking them to a friend of his who can resurface and regrind them today. Counting on his memory at times, is rather risky though!! Supposed to have them back in a couple days.

This is one thing I've heard also about this head swap being compatible and not needing rocker stands, seeing as how I now know I have 6 bolt valve covers:

"The only "maybe" year is '63, they changed to the 6-bolt valve covers in late '63 but retained the old style rocker stands."

Thank you

Well I would like to know if the 452 heads make any more power than your old heads, which are probably the closed chamber 516 head. If they are 516s, hold onto them. Ok C Ya

I was planning on holding onto them, even though buddy originally said he wanted them as kind of like a core deposit. He has since changed his mind and basically said mine are junk, for any of his needs.

Yea most people throw them out. But I saw a post where a guy was running high 10s with ported 516s. Also had bigger valves.

High 10's is getting it on pretty good.

Typing error, LOL

Easily possible to get into the low 11s with a ported 516 head with just a 440 , non stroker

Maybe easily possible with a 440, but we're talking a puny 361 here! LOL

Almost can't believe that for a big block, the 361 was only rated at 265hp. Was this supposed to their idea of an economical motor, back in the day? Sure not economical, IMO, which is part of why I want to get either different heads (so I can quit adding that $4.00 a shot Gunk crap) or get the valve seats hardened on my heads.

My mistake, he was running 11s with the 516 heads. But thats still darn fast in a Duster! And 1958, seems you are just learning about these engines. So not a bad idea to learn on a 361. If mistakes are made, your not blowing an expensive motor. Then later on you may want a 440 or even a stroker. I learned alot on my old 383, now I'm up to a 451 and still learnin! And yea I did blow up a few 440s along the way! Lol. Its part of the learning process.

Unfortunately, I'm not the least bit mechanically inclined, so any work I get done I either have to pay some one to do or get some one who owes me a favor for working on their computer.

Have come to the conclusion that I don't want the 400 heads. The loss of compression and the fact my heads are closed ports vs. open ports, means I will suck gas like a fiend!!

I was just stopped, on some RR tracks of all places, by a guy admiring my car, this weekend. He gave me his address and said to get a hold of him. Says he has a bunch of Mopar parts. Hopefully, he has a Federal power steering pump AND a set of heads!! If not, then I will get a hold of you about that power steering pump you said you have. Did you say if it was a Federal, or not? What's those last 3 numbers on 361 heads? Is it 516?

The 516 heads came on the big blocks,361 thru 440, from around 1964 to about 1967. Not exactly sure on the engines and dates. In 1967 the 440s had the 2780 915 head. Better flowing ports, and the HP 440s had the 915s with a larger ex valve. Was 67 the first year for the 440? Not sure if any of those came with the 516 head.

I thought I remembered my friend saying 516 also as did you a couple posts up. Was just double checking.

Going to that guys house this morning to see what he has. He did say he has a few power steering pumps, but wasn't positive about what heads he might have.

Thanks