I'm wondering how much work would be involved converting my 1985 911 carrera into a front-engined chev big block powered 10 second drag car.

 

I've never done that particularly conversion but:
- Again, my catch phrase: you can do anything with enough money.
- This would be an interesting conversion but not easy, nor when done, particularly competitive.
- First, I'd recommend making it a mid engine V8. There isn't a lot of room up front (you'll need most of what you can get easily for the radiator, etc.). You'd have to mount the engine well back in the car, cutting the firewall (nothing wrong with that in a drag car except you weaken the car's body structure so much), and the engine would intrude on space you need for the driver. Finally you would need the mother of all hood bulges and what would result would not look like a Porsche. And you'd have a lot of time to put in making and fitting a driveshaft, etc.
- I'd use a modern, current-gen Chevy V8, at least an LS3 from a current 'vette or an LS7 (Zo6) or LS9 (ZR1)- these are lighter but produce much more power than the older generations and while they cost more, you're going to spend a lot on this project or it won't work, so do it right.
One thing to think about is that while you could get into the tens with an older V8 (say a much modified LT4), ten seconds really isn't impressive. The '98 Camaro my son keeps for us is licensed and street driveable, and at its best it does the 1/4 in the nines. All this money and effort, at least aim for a car that can win once in a while. Right now, mid-to high nine second 1/4s are about the limit for cars that drive to the track (rather than trailered) so . . . in this car (ultimately about 3000 lbs) you will need about 750 HP (pretty easy with a LS3 modified)
- Thus, put a built LS-something behind the driver, where the rear seats etc., are. Use a transaxle - not sure what and how: I'd spend money here and probably get whatever is used in the SuperPeformance GT40 replica (extreme ones can do 10 sec 1/4 miles so they can obviously take the power).
- If I were going to do the work myself I'd estimate $25K for materials and parts and three to four years of commitment. I'd need a lot of welding or hi-tech bonding. If I were having a shop do it, I'd say you'd need the Porsche and about $120K.
- Once done, with, say, a build LS3 or LS7 or LS9, the car would have the power to do ten second quarter miles, but take quite a while to sort out, It doesn't have the wheelbase for a good drag car. and it would be twitchy and maybe even dangerous until sorted out:short wheelbase, much modified or all home made rear suspension and frame attachments - it would take talent and time (and $$) to get the suspension squat and toi in and everything correct so you could launch well and stay in a straight line for something like 10.0 at 145 mph.
But it would be fun.

 

Guys have done the v8 swap keeping the motor in the rear. Renegade hybrids has a kit IIRC.

 

I also have heard of this Renegade hybrids kit, which might work for you.

 

well the cost will be almost $1000 to $1500 approx in my rough estimate.

 

Wow. This thread was well over a year old, but then your estimate is low by over an order ot two of magnutude. A good LS V8 - something that is going to get the car into the tens as the orignal post mentioned, will cost $5000-$9000 (depending on how long you want it to last, from only minutes to bulletproof). But conversion labor and various small stuff including sorting out the car will run $18K or more, if you want only a drag car, but will run about $25-$35K if you want a streetable car that is in any way something to be proud of. Add a requirement that it still handle well, and you'll spend around $100K on the conversion.