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70RamAirIIITA · 01-29-2007, 08:39 PM

Hey gang, I'm in the process of purchasing a rough but solid '70 T/A less engine and tranny. It does still have the original 3:55 Safe-T-Track rearend. Rather than spending a ton of time trying to track down the #'s-matching RAIII 400 (WS block/#12 heads) and M-21 tranny, short of laying out big bucks for an LS6, I was thinking about building the crap out of a 454 and dropping it into the bird (painted Pontiac silver-blue of course

).

I've come across a couple of different sets of heads and was wondering which would work better for high-performance; the first set are '73 open chamber oval-port 049's off a 454, the second set are 67-68 closed-chamber oval port 215's off a 396. I also came across a '74 454 long block; from the research I've done so far, supposedly the '72-'74 454 blocks contained a higher percentage of nickle. The same guy with the 215's has a '66 396/427 2-bolt block (no crank, rods or pistons) for sale as well.

Is one combination better than the other? I was thinking of dropping in the big block due to early 2nd-gen Camaro's coming with the optional 454 and it "should" be a direct bolt-in - am I correct? Any advice would be greatly appreciated - thank you in advance!

Randy

charles vance · 09:56 AM

My bad

Mr. P-Body · 01-30-2007, 09:53 AM

Randy,

The 454 heads are door-stops. The 396 heads are a bit better. The best oval port heads are the '68/'69 350 HP 396/390 HP 427. They have the large intake port with the "open" chamber.

Installing the BBC in the T/A will "fit" using Camaro parts, as you alluded to. However, due to the extreme weight of BBC, handling will be destroyed. It will no longer drive like a T/A.

For the same money, one could have a 461 Pontiac, based on a 400 block. Weight would be right for the car, and power is at least as good as the BBC, if not better. BBCs aren't "rare", but they aren't "cheap", either. It's not like building a 350...

Jim

charles vance · 01-30-2007, 09:55 AM

I'll go with the 049 oval port heads. You would need dome pistons to get the compression up. If the car has chevy frame mounts I think you'll be ok.
Building the crap out of a BBC? Why not go turbo! more power, better street ability.

http://www.turbomustangs.com/smf/index.php (Do a search on BBC)
http://www.users.interport.net/s/r/s...dc.htm#BBChevy

70RamAirIIITA · 01-30-2007, 01:12 PM

Well, maybe now my question is all for naught - I might be picking up a '71 455 block/lower end from one of the guys on the site. I also came across a pair of #12 heads as well. Will the heads fit the 455 block? Thanks for the input guys, I appreciate it.

PunchT37 · 01-30-2007, 10:37 PM

The heads will fit the 455. But with common flat top pistons, the compression will be about 11:1 to 11:5 so if you want to run pump gas, it will be too high. Might look into a dish piston for that setup. Thanks for saving that T/A.

70RamAirIIITA · 01-31-2007, 01:03 AM

Thank you for the information; I seem to remember reading somwhere that if you put 400 heads on a 455 that the CR would be pretty high. It will be mainly street-driven so if that combination comes together, I'll be sure to get dished slugs. I'm having a helluva time tracking down the WS block, so I figure if I can at least have the correct heads..............I just think the 455 has more potential as far as punching it out. Am I correct in that the 455 has more low-end torque than the 400? What kind of affect will putting the 12's on a 455 have?

As far as saving the T/A, wait until I post pictures of it, it's enough to make you cry. Hmmm, let's see, molded rear fender flares, diamond tuck interior..................needless to say it's going to take a lot of work, but it will be well worth the journey of bringing the Phoenix back to life!

Mr. P-Body · 02-06-2007, 10:56 AM

The 455 as delievered, DOES have more potential than a 400, but... There are now quality "stroker" kits for the 400 block, which is both more plentiful and physically stronger than a 455 block.

Running the "12s" WILL net you a static compression ratio in the 12:1 area. WAY too high for 93. Good heads, though. Among the better D-ports. Pistons are going to be the sticking point, but not too big a one. Pontiac Dude sells very nice forgings, made to order (including dished) for a reasonable price.

E-mail me if you'ld like some 1-on-1 discussion about the potential of the Pontiac. [email protected]

Jim

70RamAirIIITA · 02-06-2007, 12:14 PM

Thanks for the info Jim. I've actually just located and purchased a mostly complete (less carb) correct WS block/#12 heads '70 RAIII engine. The 400 definetly sounds like it has more potential than the 455. I'll touch base with you at your email.

Randy

Ron Landis · 02-06-2007, 02:33 PM

and amen!!!!

70RamAirIIITA · 02-06-2007, 07:23 PM

I hear you bro - what in the heck was I thinking??? Awww, the blasphemy! I'm surprised I didn't get of hate mail from the community knocking sense into my head!!! Now to start planning for the for the 461 RAIII stroker (as Mr. P suggested)..........

7T2 · 02-19-2007, 10:34 AM

consider also the # of comparitively priced new parts coming out for pontiacs this year-
canted valve heads, forged cranks, new intakes. how 'bout a 501ci street motor in a 400 block with very little, if any, clearance grinding needed?
but the real satisfaction will come from all the chev head scratchers that just got their lunch money taken by an engine they previously dismissed!
jim

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