Heliaster,
fyi, i have verified with marti auto, there were only 75 gt/cs cars built with a 4spd trans and a locking diff. and thats with any engine, mine is a j code 4spd with locking diff. i would sleeve your 289 block and put it back as exact as your able. then if you want more ponys, i would build a completely seperate engine and stroke it to at least 4 in. any bore (289, 351) will run extremely better, and with 3:00 gears get better mileage,(if cammed right). don't thow your block away, i didn't get the matching numbers block with mine, and it's kind of a bummer.
fyi : 2008 shelby gt 500 engine: 3.552 inch bore x 4.165 stroke
JBART, stroke it to at least 4 in? on a 289/302 small block ford a 3.4" stroke is the maximum with a .030 bore gives 347 ci. i've heard of 351W being bored and stroked out to 383ci (thats a 3.7" stroke and 0.060 overbore)...but when you mentioned 4" stroke, i wondered if it was even possible on a 351...here's what i found:
We've all heard the quote "There's no replacement for displacement", so let's build our stroker as big as possible, there are kits that can take a 351W all the way to 454 cid, and bigger is better right? As with everything else, bigger is not necessarily better. There are several considerations to make when engineering the displacement of a 351W stroker, rod ratio, cylinder heads and rpm limits are just a few.
The easiest and most popular stroker combination is offset grinding a stock 351W crank to 3.7" stroke, with a .030 over bore you've got 377 cid and with a .060 overbore you're at 383 cid. Eagle makes a high quality, affordable steel rod that works very well in this application. It is 6.200" long and features Chevy small block journals. Using this rod gives a very favorable 1.68 rod ratio and is just as happy revving to 6000 rpm in a mild street engine as it is at 8500 rpm in a 15:1 race engine. The rods clear the block with room to spare and no exotic crankshaft balancing is necessary.
Other popular kits offer cubic inch combinations at 408, 414, 427 and even 454. Most of these kits start with a 400M crank that is extensively modified to fit the Windsor block and feature a 4.00" to 4.25" stroke. While more cubes may sound appealing, it isn't for some applications. The primary problem is cylinder head efficiency at higher rpm's. Most small block cylinder heads were designed to be used on a 289 through 351, they weren't designed for the near big block cubic inches of a large stroked Windsor. Most don't have the port volume necessary to efficiently feed engines larger than 400 cid. So in a maximum power effort, the returns from the added cubes fall into the category of diminishing returns. Street engines are less sensitive to the high rpm airflow needs and can offer plenty of low end torque with one of the bigger strokers. Revability with 4.00" or more stroke is also a concern, the lower rod ratios and subsequent rod angles can cause excessive piston skirt wear and slapping when cold that can sometimes sound severe.
So, what you are saying is possible, but not very practical. I'm wondering why did you say at least 4in? is this because your shelby has a 4.165" stroke? that is a completely different design...you are comparing apples with oranges..unless Zac wants to go with an overhead cam, crate motor...
i saw someone selling a 2007 Shelby Motor for $14,000 and the 6 speed trans for $3200...that might add value to the california special, but its pretty custom and makes your car more of a restomod, which is fine if you're planning on keeping it forever...
my recommendation for Zac...goes with what Paul said...
from my experience (you don't need a 4" stroke)...i bored and stroked my original 289 block for 347 and modified the cast heads and bolted on aftermarket parts and it didnt do the job...i now have that block sitting in my garage....get yourself a 87-95 5.0 block...bore and stroke that to 347 (3.4" stroke)or 331 (3.25" stroke) and get yourself some $2000 aluminum heads and a big hydraulic roller cam...this would be a more practical way to have a performance engine in a car that you CAN drive on the street...if you want an engine that really revs...then don't stroke it...build yourself a 7500rpm 289 like Robert Cambell has...
just fyi...my 347 revs to a maximum 6500rpm safely....if you want 7000rpm dont get a 347 stroker....leave it as a 289 or get a 302 or get a 331