Supercar Reunion #8

[mike s]

65 400 is a destroked 425 having been an oldsmobile nut for a number of years 70 455 with all the correct pieces is a top notch choice only thing better is a 70 W30 455 just my 2cents hope it helps

[retengw31]

Well this may be more info than you need, I wrote this in response to an email from Rob before I saw this post. Anyhow, here's the breakdown on 425 vs 455 with the 400 derivatives of each added in.

Anyhow, the 425 is basically the same as the 455 except for the larger stroke on the 455 (4.25) vs 4.0 on the 425. Bores are same at 4.125. The 425 was used in the big cars from 65-67 and the 455 replaced it in 1968 and ran until 1976.

The shorter stroke on the 425's made them higher revving (with more peak horsepower up high), but less torque all through the power band. They both had excellent metallurgy in the blocks (at least the early 455's did), and used very similar heads (67 425 and and 68 455 heads were both C castings and identical). 425's also used a forged crank vs a nodular iron cast crank on the 455's. Later 455's used crap cast iron cranks (73-76). 425's also used long 7 inch rods.

425's had some wierd valve and cam arrangements. Each year they tried something new until they realized, they just didn't last in the high rev areas (over 6k). They tried to keep as much oil down low on the cranks as much as possible (huge main and rod bearing diameters) and valve train durability suffered as they addressed the oil problems. 455 didn't experience that as it wouldn't run much above 6k.

65 425's (A blocks), had a 45 degree lifter bank angle with the standard .842 dia lifters, and crappy valve hold downs and pivots. In 66 they went to the B block with a .921 dia. lifter, 39 degree bank angle, and much cleaner and better valves and rocker arrangements. That carried through 67 into the 455's in 1968, but they went back to the standard .842 lifters in 68 also. All 455's are 39 degree bank angles with .842 lifters.

Both the 425 and 455's had big intake valves (2.07) and small intake valve (2.00). Toronados got the 2.07's. Both had 1.62 dia exhaust valves.

The 400's in the 442's were derivatives of these engines but with smaller bores. The 65-67 (E blocks)were almost perfectly square at 3.99 x 4.00, but the 68 and 69 (G blocks) had to go way down to a 3.875 bore with the 4.25 stroke to stay at 400 (GM edict back then). The 65-67 400 used the same sand core for the water jackets as the 425, so could easily be bored out to 4.125 (or even 4.250) whereas the 68/69 400's had a unique sand core and was a thin wall casting. Couldn't go much bigger than 60 over without danger. They weren't that great of a performance engine, but great for cruisers and Vista Cruisers.

So to answer your question, I'd go with the 455. Much more plentiful, more bang for the buck. Can keep compression down, and use moderate gearing. You'll have to go way up in compression and gearing to make the 350 come alive. I run a 4.56 and Casey runs a 4.33. Both are very high compression engines.

If you're into Pure Stock or FAST racing, the only combination for a 68 with the 455 would be a Hurst (silver/black) and the 350 would have to be a Ramrod W31.

I'm doing a 68 W30 with a 67 short stroke 400 right now. Won't be able to run either PS or FAST, but may be OK in the new Factory Appearing Class at NSCA. Engine ran 11.60's all day in Chris Hemminger's 71 Cutlass Supreme. Has a Hurst type treastment in red and black.

[SmallHurst]

Dave,

Thanks for the lesson! I have watched ROP for over 3 years and did not get as much out of them as I did in reading your segment. I would have had to sort out too much BS and bickering!

[retengw31]

Thanks, Rusty. Seems to be a lot of new "experts" over there now, too bad, that was a great site until recently.

We'll be looking for you this year with a pair of nasty W31's. We love Big blocks for snacks. As long as someone doesn't hide my pants again....................

[DirtyS]

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We love Big blocks for snacks.

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Bring it.

btw-That Pure Stock article listed Casey's car as having 4.66's. Typo or did he change em?

That car really impresses me. As does Detweiler's.

[SmallHurst]

Hey Dave,

If the world spins in the right direction, I will plan on making my way to Stanton again! I was really hoping to get a chance to whoop up on you with the "old" motor, now I just have to pray that you will blow through the clutch or the tires! So far, in my memories of PS racing, the two most anticipated races were 1) Martin '03 when Rob was racing your car (too bad I came off the line sideways and I had to petal like John Force) and 2) when I raced the '69 H/O advisor at Stanton last year-difference at the finish=.001! Better get your game face on!

[DirtyS]

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Nice Car!
I would enjoy seeing more of it at any scheduled shows you plan on attending this year.

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W30's are some bad looking bastages, eh?

I hope to make the the BOP race at Da Grove on June 5 th, and the FAST race on June 17th, but that all depends on work.

It isn't a show car, but I do have fun with it.

Going in the rotisserie this winter if things work out.

[tom406]

All right, I'm not going to miss it this year. I bought plane tickets and a room at the Holiday Inn last night. (For all of you Washington board members, I got nonstop flights from Seattle and 3 nights at the Holiday Inn Collinsville for less than $500 total via Travelocity online! You guys are going to have to come up with other excuses now....) I just need to secure my place at the banquet and I'm all set.

I'm trying to decide if I need a rental car or not. I think I should be able to shuttle/cab/bum rides enough to get me through the weekend. Opinions welcomed (unless its "you seem like too much of an arrogant bastard to ride with any of us", just paraphrase that into "you might like the convenience of a rental car").

Hope to meet many of you in person, and see some great racing and great cars.

TOM BRESKE

[Mr. T]

Ok guys, Darren twisted my arm hard enough, so I will be seeing all of you guys at SCR8 in September. Looking forward to it!

[DarrenX33]

Shhh. It'll be a good laugh. I told him the dates were changed. He'll be showing up for the International Gem & Jewelry Show, Inc.