I know this is a total newb question, and I truly have done quite a bit of research but have gotten lots of conflicting information. I've also gotten a lot of opinions that vary wildly and I can't even be certain these people know they're talking about. I do have experience under the hood of a car, but very little experience with classic cars, and no experience with corvettes. So here I am on a corvette forum hoping to get some useful information from guys who can speak from experience.

My wife and I recently purchased a '70 convertible and am trying to decide what the best route to take would be for us to reach our goals.

This is not going to be a dirt cheap budget build, we would like it to look nice and everything. That being said, we hope to spend as little as possible to reach our goals. We're not 'ballers'

This will be almost exclusively a street car. I'm sure we will be taking it to the drags from time to time, but solely to enjoy ourselves and to see what our car can do - not worried about being competitive in any particular class or anything. It won't be seeing daily driving duty, but may be used for road trips from time to time. I would like a transmission that will keep rpms down a bit when cruising on the expressway.

As far as power goals... I would like to make at least in the neighborhood of 450-500 whp. Ideally close to 600, but from my experience when you are in that high power range each horsepower starts costing more and more.

So, now for my questions. What is the absolute cheapest way to reach these types of goals? What is the most cost effective motor that will (for the most part at least) bolt right in? Will any 350 of any generation bolt right in without custom motor mounts? I can handle an engine swap, but would really like to avoid cutting up my car to get something to fit. I've considered a 454, but my logic tells me that a 350 could make more torque than I could ever use on street tires while saving a good amount of weight. I'm not DEAD SET on retaining the carb, but do like the old school sound. Unless there are HUGE benefits that make dealing with a fuel injected motor in a car that wasnt designed for it worth it, I plan on staying carbureted. And for transmission... I would like to keep it manual. Maybe 700R4?

Sorry guys, I know that was long winded. Any info/threads/educated opinions you can offer would be greatly appreciated!

Edit: I forgot to mention that I prefer not to use nitrous, but am not opposed to the idea of supercharging.

 

I suppose a good starting point is telling us what you 70 has under the hood to start with. And being new pics are a must.

 

Well I can't speak from experience but I can tell you that you are starting off the right way by asking all the questions. There are questions you will not even know you should be asking but I can give you an idea what's involved here.

Depending on how far you want to go, I would start by examining what you have to start with. Is the frame sound? Will it need work? How much work? How about the body? Interior? You need to do all the dirty and mechanical work first before doing cosmetic work like body and interior. Some paint jobs can cost close to $10k.

For the motor, maybe buy a crate engine ready to run and rated at the hp you want. A 700R4 trans is a good automatic trans that has overdrive and allow you to cruise at a lower rpm and save some gas. A stock 700R4 will probably not live long behind 600hp so you may need to get one that was beefed up, I think TCI sells them.

Last part of the driveline is the differential. If you stay with an automatic trans you won't have to beef up the diff as much as with a manual trans, (the auto trans absorbs some of the shock when you floor it). Anyway, maybe this will give you an idea of where to start. And always have a plan before you start doing anything. Just my opinion! Hope this helps!

 

Hi Nate,
70 Convertible.... NICE!!!!
I read your post and it all seemed well thought out.
One thing scared me.... "absolute cheapest way". I don't think a 500 hp Corvette goes with that phrase.
You need to start planning the BUDGET now too!
Good Luck!
Regards,
Alan

 

you are right about one thing, there are a lot of varying opinions here.definitely crate engine to begin with though, if you stay with the smallblock you wont have to worry about pulleys, springs etc.
the zz4 and the zz383 are the most recommended swaps here that i have noticed.

 

600 streetable rear wheel horsepower from a gen1 small block is really asking alot! At that level, you will have a tempermental beast, most likely. If you want 600 ponies, and still have a nice idle, and some low end, you're probably gonna have to look at some sort of turbo or supercharger setup. I suggest you start reading Car Craft and Hot Rod magazines, they have "457 horsepower from a Gen1 for $3000.00!!!" types of articles from time to time. Then when ya find something you like and can afford, use it as a "recipe", just like you would bake a cake.


Scott

 

400 or more whp will require a bit of strengthening of other driveline components like the u-joints, diff and such if you intend for it all to live happily forever, especially if a pair of drag radials or slicks might enter the picture. The easiest path to serious pump gas HP is a big block. Forced induction is mighty tough to fit under a reasonable hood height; important if you wish to road trip the beast... peering around a 4 inch or higher BB hood for 6 hours will make you hate life. If you really want 600 HP, put a solid rear axle conversion on your must have list... some here keep the IRS alive at that level but a 9 inch Ford is practically nuke proof if built with the good stuff. Think hard about your priorities because compromises need to be made to stretch the practicality envelope.

 

502 CID and beef up everything behind it.

 

natemo, Don't know the condition of the car nor do I know how much you know about cars. My opinion you will need a min of $20K to get anywhere near what you want. I rebuilt a 69 vert daily driver, kept the small black, etc. To get one of these cars looking and running top notch is no easy task.

My $0.02 the 4 bolt small block with the TH400 tranny is a good drive system and works well for me. The big expense was paint, suspension, brakes, interior and chrome work. I wanted a cor that looked and ran well, I don't race it. The thing I found was nothing was "cheap".

Good luck with the project!

 

Hmmm, well I guess I'll throw in a little here. First off, nothing on that car is rated for 400 to 600hp, Second, congrats on a great car! And welcome aboard
3rd, 400 to 600 on the street is a serious waste of $$ unless you have a couple boxes of it laying around. 350 to 400 will do all you need for just running around and the like.
I lost count, but next, Keeping the rpm down is a job for an OD tranny, several routs to do. I built my 2004R as a stage II for around $800, BTO will sell you the same thing for $1800.
Drive train will need to be done from end to end, couple more k$. Engine there is no limit to what you could spend on mods. What I would do, depending on the condition its in now, is drive it around for a while, figure out exactly what you want out of the car. These things are not the super car people think, they are old tech, rough riding, expensive toys that are Still the coolest thing on the road. They take a lot of maint, and a lot of $ unless you are handy with a wrench.
That all said,
Post up some pice, we will be Very Happy to help you spend a few grand!

 

My 2* ...which ain't worth much

Whatever way you decide to go , make sure that it's without a doubt what you Really Want !!.....Pay once , Cry Once !

Good Luck !!! and Have fun with your new Baby !

 

I found this out when I restored mine. Cheap and Vette do not go together. I had one with almost 600hp and it was a chore to keep it lit from stop sign to stop sign. It just wanted to go. My next was a 400hp and it behaves very well. Someone stated earlier you need a turbo or supercharger for 600 horses and that's about right, unless you go juicing it. My advice is one thing at a time. Don't start working on several parts of the car before you are finished with any others you have going. you will be happier and your hair won't fall out. It took me 5 years and almost $25K to get this one done.

Good luck.