1976 motor rebuild
Thread Starter
Intermediate
Joined: Jun 2009
Posts: 25
Likes: 0
1976 motor rebuild
Just purchased a 1976 with 48k miles on it. My husband wants to add a little more power to it this winter and would like to know what a basic engine upgrade would give us a good boost in HP. We have the L48 with a 4 speed. I do not want to loose the original block and heads, but would like to know some basic ideas that we could do to increase the HP. (Bore size, cam, retooled heads, manifold, carburetor).
second, it is a little bouncy in the back end. What kind of shocks and should a new bushing set help with that?
Thanks for the help. I am excited to own the vette.
Thanks,
R76
second, it is a little bouncy in the back end. What kind of shocks and should a new bushing set help with that?
Thanks for the help. I am excited to own the vette.
Thanks,
R76
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
If you're concerned about originality, a good compromise is to store the original engine and drop in a crate.
If you're just looking for a little more oomph with the stock engine, the best power/$ is a cam upgrade. The L-48 cam is pretty mild (.390/.410 lift) and a modern cam in the .450 lift range will provide an excellent power increase for a pretty reasonable investment. Combined with an aftermarket dual-plane intake, carb and headers you've got a very solid and "seat of the pants" boost. I would not invest in porting the existing heads or going any further in terms of engine mods; you'll find a crate at that point to be more cost-effective.
Many answers here regarding shocks, spring replacement and other upgrades - my only suggestion is that you approach the suspension holistically as a system and not just do work to the rear.
If you're just looking for a little more oomph with the stock engine, the best power/$ is a cam upgrade. The L-48 cam is pretty mild (.390/.410 lift) and a modern cam in the .450 lift range will provide an excellent power increase for a pretty reasonable investment. Combined with an aftermarket dual-plane intake, carb and headers you've got a very solid and "seat of the pants" boost. I would not invest in porting the existing heads or going any further in terms of engine mods; you'll find a crate at that point to be more cost-effective.
Many answers here regarding shocks, spring replacement and other upgrades - my only suggestion is that you approach the suspension holistically as a system and not just do work to the rear.
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
the good news is the small block chevy engine has the most affordable aftermarket parts available and is very responsive to most upgrades.
1976 was a tough year for auto makers trying to meet unrealistic smog regulations before on board computers existed.
a nice street mild cam would be the first thing I would change (and get a double roller timing chain set while your in there)
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Exhaust
See what many refer to it as my Exhaust topic. http://www.corvettefaq.com/c3/ganeyexhaust.htm
Cam which L-48 needs badly. AL. intake can be done at same time as cam.
Tuning & Timing incl. carb. adj.
See if rear spring is steel or composite.
See what many refer to it as my Exhaust topic. http://www.corvettefaq.com/c3/ganeyexhaust.htm
Cam which L-48 needs badly. AL. intake can be done at same time as cam.
Tuning & Timing incl. carb. adj.
See if rear spring is steel or composite.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
A Vortec head swap with intake and a cam would work wonders on a basically stock engine. I know you wanted to keep the original heads, but just store them away for posterity. You can do searches for Vortec head swap and there is tons of info out there. Be careful on cam selection with Vortec heads, there are lift limitations. If you absolutely have to keep the original heads, then just a cam and intake swap will help. Bear in mind a cam swap without engine removal in an a/c C3 is not an easy job. Also changing to a high-flow catalytic converter will help too. The '76 has a pancake style converter that clogs pretty quickly.
A swap to TPI fuel injection is also quite a wakeup for a stock engine. Just a thought. I have it and I love it.
A swap to TPI fuel injection is also quite a wakeup for a stock engine. Just a thought. I have it and I love it.
Drifting
Joined: Aug 2007
Posts: 1,838
Likes: 13
From: Kingman AZ
I would suggest also to swap your heads. I know you want to retain the "stockness" of the car but a set of aluminum heads with a combustion chamber size of 64 CC's will bump up the compression. Store the heads for the future should you sell it. A decent cam, aluminum heads, aluminum intake and the stock carb should put you at about 300 to 350 hp on pump gas
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