I need help I'm looking to bore my L98 from a 4.00 to a 4.03 and add a 4inch crank. I have an 87 but what is the best transmission to actually use is it 700r or can I use a TH400 I'm really new to this and plan on driving somewhat daily but still want to pull a Ricky Bobby every once in awhile

 

The 700 can be built to handle it.

 

So straight out the box isn't going to work?

 

It will work fine until you burn it up. As noted in post #2, "It can be built".

 

Just and FYI 4.03 x 4 = a 408CID not a 383 CID.

 

700r4 can handle up to about 350-400ft-lbs in stock form, beyond that you're on a ticking clock. It may last 50K, it may not last 5K miles. Just depends on how you drive it. Usually the 1-2 shift goes first.

Add an additional cooler, upgrade some parts inside, upgrade your TC, and it'll handle it fine. I'm putting 500+ torque through mine.

 

I take it rebuilding my current transmission is out of the question? Thanks guys bought the car for $1000 and fell in love with them. I have zero knowledge. So the 4.03 bore and 4in crank turns this to a 408?

 

What was said that would lead you to say this? I repeat - It can be built. Yours or any other one.

 

Besides here everything I read and watched said it would need a 700r4 or Th400. Mind you my help has been limited however thanks for the help and advice. I can't wait to post her on here

 

Dude!!! You HAVE a 700R4 in your 87!

 

Holy Ish didn't know like I said it's my second project ever lol I was about to spend $3700 for a new one 🤦🏿‍♂️. I also read on another thread I'd need a bigger intake manifold if I bore it out?

 

You don't know enough about your car to start modding it right now.

Take your time and learn the car.

 

I'm only doing it because everything has to be replaced anyway for the most part car has been sitting for 5 years just replaced the brake system (booster, cylinder, lines, calipers ect) and I have a cracked head so if I'm spending it might as well one shot it

 

Your car, your money and your future frustrations. But you are ignoring some good advise from Vader86. Remember, you asked for help and there are many, many people here that know what we are talking about. If you are going to ignore good advise, then don't ask for it. As stated, you don't know enough about your car(or by the sounds, automotive in general) to jump in the way you are. Five years of sitting is no reason to go goofy replacing **** *****-nilly. Twenty five, I might agree. But not five. Were all those brake components shot or did you "one shot it" just for ***** and giggles?

 

I'm not ignoring anyone I'm taking this all in and you're right I'm a day trader not a mechanic. All the components were shot. It was used as a swinger for side shows blew a head gasket and they left it after that. Booster was rusted completely. I had a water hose as a hose substitute when I bought it so it's in pretty bad condition

 

Yeah, same here... ~450-470 ft-lb 383.

Upgraded clutches and bands, firm up the shifts and a good torque converter too (Hughes 2500 for me). I don't thrash on it constantly, just some spirited driving on occasion. So I'm expecting it should last a long time.

 

Thanks the trans kicks hard going in reverse so I figured it was going out. I figured it is going out as well. This is perfect so I know what parts to grab. Some think I'm blowing them off but just absorbing information main reason I signed up

 

Welcome to the Forum.

There are numerous 383 stroker kits available from the big guys at Summit and Jegs to name a few. It is better to get a complete master kit.
Just rebuild your Chevy small block... If you bore it over do the 383 stroker you will need to have a good machine shop to clean and check your block and get it prepped to do the clearance needed for the stroker crank. Find a machine shop that could also rebuild your motor and have it blueprinted and balanced.

You are going to want to keep away from the the Tubro 400 as it is an old school 3 speed transmission without an overdrive and requires modifications to make it work. It would be better to just have your transmission rebuilt with beefed up internal parts. The 383 will generate 30hp more, keeping everything stock but your will pick up 40lbs to 50lbs of torque so your stock 87' will make about 390lbs of torque a good stock rebuild with a few upgraded components would hold up for years of medium abuse.

As others have said, keep learning and researching, the good advice about a good converter and I would add better rear gearing will make a significant improvement in how the car feels and drives. To recap, just rebuild both your major components a nice complete stroker kit, rebuilt tranny, converter and a good machine shop or engine shop. Also your budget and wish lists can easily get out of hand so plan wisely and have a good idea of what you want and can afford. It will take time and money, regardless, but using the upgraded stock engine and transmission means no headaches in trying to make something work. Especially with your dash and your stock computer, intake and injectors etc.

Once again Good luck... Cheers

 

Thanks I'm simply learning and building my supply list and figuring out how far I want to take this. I'm not trying to run under 10 seconds but just when I punch it it gives me a little more than how it started. I also appreciate the heads up on the crank clearance. I've gotten a lot of really good advice and help here. You guys are really helping me out and minus two guys have taught me a lot in a short period of time really made me learn my specs