I would like to replace my 330 and put in a 455, going in a 65 F-85. What would I need to do for the transfer? New engine harness? Mounts? Front springs? Like to add headers. any other answers and suggestions will be helpful, Thank you.

 

Good luck on headers for a big block in an early A body. Very expensive.

 

The 455 is externally identical to the 400 used in the 1965 442. It's pretty much a bolt-in. As Mark points out, most header manufacturers have stopped offering headers for the narrower 64-67 cars due to the lack of demand these days. ARH headers fit but are extremely expensive. Headers for the 68-77 cars that are readily available are hit-or-miss as far as fitting. Each manufacturer routes tubes differently, so some come close, others miss by a mile. The reproduction W/Z manifolds used in the 1969-72 442s fit just fine and are a good compromise between the stock manifolds and making headers fit. The W/Z manifolds are internally divided for improved flow over the original 1965 BBO manifolds.

Your 330 accessory brackets unfortunately won't fit the BBO. You'll need brackets from a 65-67 400 or 425. Get a radiator for a 1965 442. You'll want a high torque starter if you don't currently have one. And above all, do NOT get "455" motor mounts. Use the same mounts as those on your 330 (Anchor 2261 or equivalent) if you need new ones.

 

I don't think the BBO headers are as much of an issue as the SBO in the 64-67 models.

 

thx, Joe

 

I think Doug's Headers still makes a good fitting header for the big block in the early
"A" body.

 

yes they do. But the drivers side on Dougs we recently got still needed some massaging.

 

You have a part #?

 

ya I’ll get it for you later

 

Thank you!

 

 

Not sure if you still need the info but I did the exact same swap from my 65 Cutlass Convertible from the 330 to a 455. It was pretty easy don't be scared off by those Ebay headers I think I paid about 200 bucks for stainless chrome headers. I did have to massage the drivers side I think a bit but nothing terrible. Use the engine mounts from the 330 they fit fine, also I was told on here and it was correct, Either use all the 330 brackets or all the 455. All my 330 brackets worked fine along with all my pullies. Don't try and mix and match the brackets or pullies. My radiator was fine though I did upgrade to a Champion aluminum . All the existing wiring is identical my car is a non AC car. I don't think its worth the extra money to spend $1500 on headers especially on a street car, use a quality copper gasket and good bolts . hope this helped.

 

Use the engine mounts and all accessory brackets on big block. Go buy 200 dollar stainless headers off eBay they fit pretty good and have fun!

 

thx 1965

 

thx 66

 

I didn’t think so either. Unless something changed. Thought SBO were the hard ones to find.

 

are these the cheap ebay headers that you guys are referring to?

https://www.ebay.com/itm/25558399786...gAAOSw7zdinNyy

 

Yes those are the ones.

 

Some info in this thread:

https://classicoldsmobile.com/forums...d-them-164721/