StingingYellow75

Fellow Vette Owners,

I have recently been handed down my father's 1975 L-48 auto coupe (stock with new Edelbrock carb), and my Nissan Maxima seems as though it would smoke it! I looked up the power ratings and noticed that, that year vette came with only 165hp and 255 lbs of torque. WOOOHOOO. My Maxima has 260 hp stock. I was wondering what inexpensive mods I could do to the motor to get some more Hp. Currently, I am putting long tube headers, a 2.5 in h-pipe (no cats), and 2 chamber flowmasters to start along with removing the air pump and a/c compressor which doesn't work. Will I even notice a difference with these mods. Taking Suggestions....... :nonod:

Corey_68

Headers and exhaust is a great start, after that a hotter cam and intake would really liven that L-48 up.

Welcome to the forum :cheers:

pillowmeto

i belive a recurve kit on the distributor should also do alot, there is a guy named Lars on corvetteforum that makes the kits to do this. If you plan to make some real power yuoll need some heads, but you can get some substancial power without them.

MAtt

Corz

good luck modding a smog vette in california.

heads/cam/intake/headers (with a.i.r. tubes) high flow cats, ignition, demon carb, K&N filter (with extreme lid) and you'll probably drop a second or two depending on what you decide to go with.

good luck

StingingYellow75

Well Smog isn't an issue for me right now. I just want more HP. I am interested in that SVE KwikCurve Kit, but can't find a dealer. Headers w/out cats and flowmasters are going on it Monday. Does anyone know the suspected HP gain of these mods by any chance. :nonod:

macx

Check out these sites - especially the big site with lots of dyno tests.
Some of them are with moderate mods using stock heads, others are
with inexpensive heads like Vette aluminum or the great Vortecs,
then others go more expensive like AFRs etc.

Using your stock lo comp shortblock, adding Vortecs with SS valves and
better springs (always some like that on ebay), thinner head gaskets,
an RPM Vortec type intake, a 625 Demon or 750 Holley, 1-5/8 long tubes,
and a Comp Cams flat tappet XE 268 (or better for street with actually
very similar power is the XE 262 - either is a very inexpensive setup
compared to the retro hydraulic roller setups) can give up to 400 hp
and 425 torque and still be very streetable. Check the 355 dyno sheets, then Part 5 of the Goodwrench buildup series. All can be done without taking the block out of the car.
http://www.corvettefaq.com/c3/goodwr...20part%201.htm http://ryanscarpage.50megs.com/combos2.html http://www.geocities.com/MotorCity/7610/dyno.htm

Here's a neat calculator page where you can calculate compression ratio with
different heads and gasket thicknesses. http://www.smokemup.com/auto_math/index.php

LFZ

suggestions.......drop a big block in it. :jester

JoeC427

:iagree:

iree75

That's the route I'm going for my 75. I get the block back from the machine shop this week. It's a 454 030 over block with a 427 crank, so a 433 then.

75Rag

Yes it will!
I've only got true dual exhaust using the stock manifolds and a dist re curve (Lars) and was dyno'd at just over 200 rwhp. (230 to 240 fwhp) That alone is a dramatic (and cheap) increase from the stock 165.

gdh

If you are going to get into engine mods later you might think about going with a higher cfm muffler than the Flows. They sound great but are quite a bit more restrictive than the Borlas, Dynomax Ultraflows or the Magnaflows. A performance engine should really be planned out from air filter to tailpipe. Good luck on your project.

Ganey

See what many refer to as my Exhaust topic. http://www.corvettefaq.com/c3/ganeyexhaust.htm
Dynomax Cerma coated headers rec. for performance.
Next more cam, a good time to do intake.