Guys,

Im hoping I could get some suggestion's from engine guys. I have a 69 390hrs. It has a stock drive train. I’m going to do a rebuild. I’m thinking about punching it out a bit. Not drag strip but around 450-475 horses would be nice. I'd like to have an idea before i pay for a rebuild.
Any ideas or suggestion would help. Has anybody had this done, and been happy with the results?
I’m thinking, roller cam, polished heads etc. But I want it to be a pump gas car with all the vacuum ability’s. Thanks in Advance.

 

If you have a numbers matching big block '69 'vette, don't modify the original engine, buy a crate motor or start with a donor engine. Put the original in storage.


Scott

 

Here's my suggestion,

Pull the 427 and stick it on an engine crate. THEN go buy a 454 engine and rebuild it. If you're really motivated, add a 4.25" crank to it and make a 496 out of it. Add a good set of heads and you're all set; if you can do an overhaul yourself.

If you're paying someone to do it, just get an engine from Mark Jones. (http://www.vortecproperformance.com/) he builds them in all sorts of flavors using ported factory heads with amazing results. I rebuild an occasional one for friends and if I were to buy one, he's who I would go with. PM ajrothm here, he has one of mark's engines, a 496 I think, and speaks very highly of it. I [i] think that's his vette on Mark's website. This way, you're not second guessing regarding the quality of work. Only a rich man can afford a cheap engine (because it ends up having to be built twice).

 

I went to that website. Looks like good stuff. would i have to modify the suspension at all if i were to buy a 496?

 

Since you've already a bb car, no. But you will need to reuse the oil pan off your 427 since they're corvette specific.

 

you say no dragracing? Yet you want that kind of horsepower? I suggest you buy the book "how to hotrod a small block Chevy"- by VIZARD I read it many years ago when I built my first engine, and still use the tips I learned in it today. In roughly 100 engine builds, I have never had one come apart in either dragracing or very hard street use

 

454 would be a cheap and easy swap to get the horsepower you want...

 

Any attempt to maintain matching number values aside...

With a decent set of heads (go with aluminum if at all possible) and a mild roller cam the 427 BBC is more than capable of producing HP numbers in that range on pump gas, and with vaccuum. Expect to bore/hone .030" over if your mill has a lot of miles. There's somewhat a dearth of off-the-shelf pistons for 427 builds, but people such as JE/SRP can set you up with pretty much anything you need. IMOE, buying direct will usually save $$$ if you do end up going with custom slugs, and in any event you can likely save some money by doing some head/CR/piston availability homework before commiting to heads.

Suggest looking at large'ish oval-port heads (to keep velocities up) with smallish chambers (to keep dome volume down), ~10:1 CR and cam along the lines of CompCams' XR276HR ground with 112* LSA (for a smoother idle, better vaccuum, broader power band...). You can pump the CR up to near 10.5:1 if you want to step up to something like the XR282HR, but I'd still spec a 112*, if not wider, LSA. Yes, there are other cams out there that will do the trick.

If you've an L88 or other tall hood, put an Edelbrock Performer RPM AirGap intake and 850 DP on it; tho you might prefer vaccuum 2nds if you've an auto and/or MPG matters much. Selections aren't so great for low-rise, aluminum oval-port intakes, but you can always have an LS6 epoxied down to match. Or, you might wish to go for a 427/400 Tri-power setup if you like the look and have the budget. A properly setup set of trips work great, and deliver amazing fuel economy if you keep your foot out of the 2nds.

Add a nice set of headers with good flowing exhaust system and IMCO that ought to hit the sweet spot. OMG, I love spending other people's money!


TSW

 

VortecPro uses a Moroso 20403 pan, it fits right in a C3 Vette chassis....

You can't build an engine that makes the power that Mark's engines make, with the quality of parts he uses, for the same or less money......

If you don't need anything REAL killer..... Just get one of his hyd flat tappet 520hp 468"s for $5,000. That thing will drive around like a stocker and still put you in the 11s....

 

 

6.0 LS1!!
I wouldn't bore any older motor unless it needed it since they are getting VERY hard to find. If you have to bore it than go the minimum it will take to get it cleaned up. Like everyone else said if it's a #'s matching motor pull it, crate it & store it and find another one to molest...