V8 swap questions thread

I haven't drove it yet. I haven't even put the engine in yet (permanently)

damn so you are where im at lol

I'm also running the stock rear end with a custom driveshaft. I'm running a T5 from a 2.3L Mustang, which is geared lower than the T5's from the 5.0l. Mine is not a daily driver. If it was, I would definitely try to get taller gearing - with my setup, first gear is just about useless - you're only in 1st for a second, then shifting to 2nd. I've heard from a number of people that the stock rear-end will last with a fairly stock V8 (not a twin-turbo setup) up front, as long as you're not doing donuts and burnouts etc.

I would say that unless it's pinching the ebrake cable that it's much easier to just get some heat shield on it. I haven't had any issues with mine. If you're going to wrap your headers, it will be cooler under the hood than my setup, so I wouldn't think you'd have a problem. If I'd put header wrap on from the start, I probably wouldn't have heat shielded the steering knuckle and the passenger side where the fuel lines go under the chassis at the firewall. Without the header wrap, I think that these 3 places are necessary to heat shield.

"i keep hearing that it isnt geared right for daily"
who says this?

this question, "im just wanting to use it to drive around here, 70 at most" let's check it out.
stock mazda rear, stock size tires, 5 speed: at 70 it should be turning about 2800 rpms no matter what engine,

you can "trick" the engine into thinking you have changed the rear end gear by using a larger diameter tire, diameter is the key. Stock 205/70/14 is 26" diameter, use a 225/55/17 which is 26.8" and knock off about a hundred rpm's at 70. How bout a 245/40/17, 24.7", that runs 3000 rpm at 70. So, your question about geared right totally depends on what tire you plan to run in the rear.

Is there a difference in gearing between an auto rear end and manual rear end? My buddy put a 350 with a turbo 350 tranny in his p/u and a rear end from a manual Mazda p/u. He turns about 3,700 rpm's doing 60-65ish. I believe the rear end is from a 84. What would be a rear end with taller gears i.e. less rpm's at highway speeds?

ive had a few people tell me this in my other posts, but im just trying to find the right answer, now to what you were saying, so im actually going to run a 17 inch rim with low pros, (idr the size right now) but im also running a c6(i know it will take away some hp but its ok at the moment im just wanting to get my truck on the road) the c6 is a 4 speed so will that math still work for me or can you tell me a size that would as you put it "trick the motor"?

A V8 in a vehicle as small as a B series, should turn at or about 2100 RPMs at 70 miles per hour.
The only way to bring it down that far is with gearing.
If you have a transmission without an overdrive, you can forget 70 miles per hour altogether, unless you change the rear gear.

That's going to depend on the transmission gearing. As I mentioned, I'm using a T5 from a Mustang 2.3l, and it has shorter gearing (1st gear is 3.97 Vs 3.35 or 2.95, depending on year for the 5.0l, and 5th is 0.79 vs 0.68 or 0.63, depending on year for the 5.0L).

I haven't specifically checked my RPM's at 70MPH, but I'm certain that I'm turning more (I'm thinking more like 2700-2800) than 2100 RPM at that speed, in 5th gear. My tires are 225/45R18, which is only 0.1 inch diameter difference from stock.

So are you saying that it would be better to have the T5 from a V8 than the 4 cyl one?
I guess I'm confused by what you mean. I have a world class T5 from a 5.0 and I am going to use the stock rearend.