Quick question for those who have already been through this. 1955 331 hemi, what cam and oil pump to use? I've heard rumors that I can use a 340 oil pump and maybe cam. Is it true? What about a distributor? r
You can use a 340 oil pump with the proper adapter but the stock pump is fine for the average street use....I don't believe you can use a 340 cam and you can use a mopar smallblock distributor with the proper adapter.... Check Hot Heads for hemi parts....
If you do use the adapted 340 pump and distributor double check the engagement of the drive into the pump I’ve seen guys having problems were it brakes or wore out and the pump stops turning. And you probably know what happens next. Also I’m told the SB distributors drive is a little short and needs to be lengthened for full engagement.
Yes. you can use the modified HH 340 oil pump.Bolt in.I used one own my RR Dodge and '92. Never had a problem..... BUT... you may need to mod the oil pan .... I did on both my Hemi engines. That was the only issue I had with running one. other than that.. ran terrific and pressure was great(sold the Red Ram... still got the '92.) Your pal....Captain Canada.
If you haven’t seen this you will want to https://www.jalopyjournal.com/forum/threads/hemi-tech-index.118764/
The 340 pump requires an adapter. The Melling M50 is a direct replacement for the 392 (and 270-315-325). The M50 uses a different oil pickup tube assembly so not 100% direct interchange with the 331-354. Melling flow tested the M50 and the High Volume 340 pump and only found a 3% difference. If you have a rear sump pan then look at the Melling 72-S5 pickup tube/screen (Dodge pickup/van). It is generally too 'tall' (sits too deep) for the oem pan but is easily shortened to fit your pan. There is no cam interchange with anything other than the 331 and 354. An LA distributor is about .300" short. You can extend the tang or replace the intermediate shaft with a 392 part or new aftermarket part.
Pretty standard hemi stuff. You need the 340 adaptor and a bypass valve blocker both available @ Hot Heads. I am currently rebuilding a '55 331 for a friend and doing all that stuff. The stock '55 oil pump is in great shape so I am using that. I don't buy the distributor adaptor. I just weld the tab on the late model Mopar electronic distributor and file it to shape 1/4" longer. That is all it needs.
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