You didn’t say “which” G-Body you’re after but I’m thinking Monte Carlo, eh? It doesn’t really matter as the Buick Regal, Olds Cutlass or Grand Prix are all very similar. They’ll all weigh somewhere between 3200-3300 pounds depending on options and everything interchanges. They all were manufactured with TH-350 and 200R4 transmissions and with some work they can all handle a 12 bolt GM rearend (although you’d be surprised how bullet proof a 10 bolt can be built!)

Ten seconds is a challenge as you’ll need 650 horsepower to push 3200 pounds through the traps in the 10 second range. You can get 350 out of a normally aspirated 350, but the likelihood of it being anywhere near “streetable” will be slim to none. You’d also have well over $10K in the engine and need to have access to race fuel to support the necessary compression ratio. Trust me; you wouldn’t want to drive it to church as the rumble in the parking lot would convince the parishioners that the second coming was eminent. The 650 horse requirement will also limit your transmission choices to a very well built (read professionally built) 200R4 with a matched TC.

If you really want to be able to run this car on the street (without attracting every Gestapo in NY) and have it go through the ¼ in 10 seconds you may want to think big block as there is no “reasonable” substitution for cubic inches. Pat McCarthy builds BBC motors for a living and he’s forgot more about making horsepower than most on this site ever knew. Give us some more specific details about what you want to see in the finished product and Pat will help with suggestions. Techinspector is also a well spring of knowledge and has access to some computer modeling software that will help in deciding components and will also help you develop a budget.

Good Luck and welcome to CHR!
Glenn