400-470 cid?

[05horse]

so my 77 TA has teh 400 CID engine.

talking to teh guy who built my last engine, he said with new crank, rods pistons, heads, intake etc etc, ( all internal parts as to keep outide original on everything but intake) he could get me to around 470 CI, and near or over 500 HP

has anyone,

1 had this done
2 had problems
3 know of problems?

i know the transmission and rear end would need to be beefed up

and i know pontiacs love low rpm, but he said most of my power would be at around 5K is it ok to go that high on this motor?

what size ( in #.#L) would that work out to?

[71' Formula 461]

I had my 70 400 block made to a 461. They make rotating assembly kit with Eagle cast crank, forged BBC rods and forged pistons for about $1500. Of coarse the codition of your block will determine the overall CI( deck height, cylinder bore size). I have read that the lifter bore webbing and block cast material for post-74' blocks are not a strong for the pre-74'. With that said I would not spend the extra $ on getting a forged crank especially if you are not building a drag strip motor. Make to have you heads CC volume checked prior to ordering pistions, you want to know what size dish cc pistons you need. I made the mistake of ordering the kit ahead of engine disassembly and ended getting cutsom JE pistions made in order to run pump gas. Butler Performance makes kits available with any size cc pistons. Back to your qustions; I have not had any problems with engine.
I have 489 HP, 571 Trq with modified cast 13 heads and Edelbrock Performer RPM intake, don't go with a standard Performer intake unless you have hood clearence issues, I had my engine dyno'd with both and achieved a 31 ft/lb of TRQ increase with the RPM intake. As for RPM range, most of the power kicks in around 4200 RPM. Using after market forged rods and upgrading your valvetrain 5000-6000 RPM range is not a concern, just there is no power up there with a cast iron head.

Hope this helps.

[WDCreech]

05horse, Your first problem would be that all 400 Pontiac blocks cast after mid year 1974, were thin in the main bearing webbing, and have been known to break in higher horsepower applications. You would be better off finding an older block.

[switz461]

Just like "'71 Formula 461"I have an '70 400 block and used the Eagle stroker kit to make it a 461. Minus the bare block and bare heads everything is new. I am using a Torker II intake with a Holley 750. I spent a lot of money, but it is worth every penny! Make sure you have a trusted shop look at the block and heads. This is a new engine and only made few passes down the track, besides the typical tuning I have not had any problems.

[71' Formula 461]

05horse,

"what size ( in #.#L) would that work out to?"

What exactly is the question?