My car now needs an engine. I was driving my 68 bird with a 455 that I bought used and running... it ran GREAT for over a year! it was NOT stock it came with a torker2 intake and I bolted on an Edelbrock 750 and she started right up. she ran great. I went to move the car out of the garage and BANG the crank broke through the oil pan. I had the engine out in about two hours looking at the damage. the mains held and the portion of the crank that held connecting rods for two cylinders broke through the oil pan. Can I trust this block? if any one is interested in giving me some advice I will send pictures of the whole thing... In any event: I need an Engine. Do I find a 400 block and build it? do I rebuild the 455? any advice from anyone would help...

FYI: I have a 455 crank for sale... some assembly required.

thanks
John

You could have the 455 block checked but I wouldn't trust it after what it's been through. A 400 or 455 would work either way. Your current cylinder heads, intake, cam etc. will swap to a 400 with no problems so the choice is yours.
Here is a good article to check out. May give you some ideas.
http://www.carcraft.com/techarticles/116_0306_pont/
Mark

Like Astro said either way. first have the 455 checked...you may be surprised.
455s are generally known for there gobs of low end. 400s are known to rev quicker. so...do you like torque ? or the quicker revs ? id just see whats out there... take your time. Pontiacs arent so easy to come by anymore .John

Check out what you have first before shelling out more money for a 400. The 455 will have more torque than the 400. Both are nice motors.

I'd get the block checked as 455s are harder to come by (at least in for me but I never "stumble" across anything); but wouldn't hold my breath.
The only real component differences between the Ponchos are the piston sizes and the crank journal is larger on the 455. If you find either a 400 or 455 you could swap that intake and your heads if you wanted to. The cam and lifters I'd probably get a new set if I had the motor out of the car, but if those look to be in good shape you could use them if you wanted to- it could be too much cam for the 400 if it was really in a sweet spot for the way you drove the 455 though. Heck you could even drop a Pontiac 350 right in if it was all you could find. The neatest thing about the ponchos was that same outside appearance on the 350, 400 and 455 blocks.
If you found found a cheap 400 and were to decide you miss the extra tork there are shops who sell kits to stroke a 400 out to the 455, but if I were in your shoes I'd start keeping an eye out for a nice 455 short block. It's what you are used to and a 400, no matter how you cut it is a step down in performance from the 455 with like components.

i have an almost 400 longblock. heads were just resurfaced and checked for cracks. i havent checked yet but i think she is bored 30 over and has a bigger cam in it and comes with edelbrock performer rpm intake. it is a 76 block or atleast i was told so. let me know if your interested. the only thing is that it blew a head gasket and the dummy that i got it from let the water sit in the cylinder for a year so atleast that cylinder will need to be bored, but other than that the rest of the them look real nice.

but to answer your question. i have a 68 firebird myself that i am restoring right now and it has a different year 400 in it and after i get the body square and save up some serious money im gonna build the 400. people tell me that they like them better than the 455 because they hook up easier?? but if your interested in the 400 let me know.

Your 455 heads will bolt to the 400 block, but your compression ratio will be way down.

I am getting that alot: Don't trust the block. the other thing is after I pull the heads off etc... I will pay a couple of hundered bucks to have the block checked out ... and that money could be going towards the next engine. I know where I can get a 455 and a 400 TODAY!.. it just takes $$$. I am going to clean the block up today and decide if I should be taking it to the shop or not. FYI: TORQE! Thats my favorite stuff right there. Looks like I may just to stay with a 455...

Astroracer: I checked out that article the night I lost my engine... I ws taking notes on the parts and looking up their prices but I could NOT find that grind on a the cam they listed in the article! Whats up with that?? Also Jeggs posted it it like this:
JEGS XTREME KITS and heck... pontiac isn't even listed! let alon one with that grind!?!?


oh well... out to the shop... and then off to the junkyard to do some treasure hunting...

Contact the manufacturers directly and get some part numbers. They have all of the parts available but, because of the low volume that much of the Pontiac stuff sees, many of the parts houses don't carry the stock or advertise it. It's out there just do a little digging...
Mark

P.S. If you are going to build a new motor I have some advice for you about bearing clearances. I have (or had) a bearing clearance work sheet for checking and maintaining clearances during the rebuild process. It's recommended to keep the clearances to the low side of the tolerance for good oil pressure at idle with the engine at operating temps.
I just rebuilt my entire computer, reformatted and cleaned out the old hard drives and put in a new one and now I can't find the work sheet... I will try to get it rebuilt in the next week or so.
Mark

Here's a site with some good stuff. Click on Torque Power for some engine builds, & the Indian head for some tech articles.

http://www.pontiacstreetperformance.com/

JIM! thanks for the link... Great stuff...

looks like the 455 wins out on that website...