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73-87 Chevy _ GMC Trucks => Performance => Topic started by: project85 on October 31, 2010, 06:45:08 am
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my truck is an 85 c-10 2wd. i don't know what gears are in the pumpkin and it has a 3 speed on the floor so some of the doggieness could be high gears but, it has a 76 vette 350 engine, the L 48. which from what i've found it has 190hp from the factory. it has original exhaust manifolds that go into a single muffler. the motor is tight and runs good just seems doggie. i wanted to know what you guys think. will it be a big difference with a pair of headers and dual pipes with a set of low back pressure mufflers. it also has a holley dual feed double pumper on it which seems like way too much carb for a weak motor like this. i don't know if an edelbrock 600 will help out any.
thanks
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not to be rude did you put the vette engine in or did the guy that you bought the truck tell you it was a vette engine ?
Drivers side block behind the head (by the brake booster) is the casting number might need a inspection mirror and carb cleaner (to clear the area) get those numbers
That will tell alot in itself
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Tune it up, play with the timing. That trans isn't doing you any favors and find out what your final drive ratio is.
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When I first called the guy about the truck he said it had a 73vette motor. When I went and checked it out someone had written 76 vette L-48. I havnt pulled the numbers off yet to confirm what it is. One of my projects for today. Also on the list, new cap, plugs, wires, pads and maybe rotors.
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The 76 L-48 Vette engines were some of the weakest ones ever put in a Vette. Not to burst your bubble but they weren't very strong even in the Vette. :(
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Let 'er breathe, too. I'm guessing that exhaust is pretty restrictive.
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The 76 L-48 Vette engines were some of the weakest ones ever put in a Vette. Not to burst your bubble but they weren't very strong even in the Vette. :(
This is what I was gonna say. But it is a 350, so it has potential.
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Oh for sure. He's got a good starting place.
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Correct me if I am wrong, but wasn't the "Big Ten" with a 454 the fastest thing you could get out of GM in the mid 70's due to emissions? The Vette was listed as a passenger car and subject to stricter standards where the "Big Ten" was listed as a "heavy duty" commercial truck and got out of cats and stuff for a few years.
The motors were pretty choked down, but that can all be fixed.
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for now i'm gonna probably put a set of headers and dual exhuast, tune up and see if it helps alittle. i know from what i read online 76 was like the worst year ever for vette motors. i have a target motor in the garage that i will build up over the winter. i gotta try to find a set of heads and find out what the gear ratio is.
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From something I read years ago, has me thinking it was pretty much the same engine in the p/u's and vettes. I had to have been reading something for or about my truck, a '76.
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Was your 76 truck real doggie or is it pretty strong. Or did you do some stuff to it to get it strong??? If I could get some idea of what might have worked for you I can use it for a blue print for me.
Thanks
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GM didn't offer a "strong" SBC in the mid-70's. That was a pretty dark period for performance.
If you are interested in making your 350 strong, here are some of the best guides for doing so:
http://www.amazon.com/David-Vizards-Build-Horsepower-Design/dp/1934709174/ref=sr_1_3?ie=UTF8&qid=1288959992&sr=8-3
http://www.amazon.com/Build-Chevy-Small-Blocks-Budget-Performance/dp/1932494847/ref=sr_1_1?ie=UTF8&qid=1288959992&sr=8-1
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A K&N air filter with an open element air cleaner would help.
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Correct me if I am wrong, but wasn't the "Big Ten" with a 454 the fastest thing you could get out of GM in the mid 70's due to emissions?
In 1978 and 1979, yeah, that is true.
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Project 85--(long post)mine had basic stuff done (air cleaner,headers, duals w/glass packs) and a cam swap when I got it. Not sure why they did a cam swap and left the stock intake and carb, slightly faster than a turd then. These next changes were over a span of years, kind of a history of what I've done. A carb and intake swap was a noticable improvement, first changes I made to it. Lost weight and went to 2.5" exhaust with Flowmasters next, again with some small gains. Shift kit to the TH350. Around this time I had a multi angle valve job done on the 882 heads with a little bowl and runner work, machine shopped talked me out of larger valves, milled the heads, still not a lot of c.r.. Re ringed it at this time, no $ for a complete and correct rebuild. Ran quite a bit better. Changed to roller rockers sometime in this period. Maybe this time frame switched to all Mallory ignition- Unilite, coil,Hyfire IVc box. Added 2.5" dropped spindles, 1 coil cut, rear flip, and a locker to the 3.08 peg leg rear. This was a big swing in how the truck behaved, next had to rig up some traction bars to combat the wheelhop. Stayed like this for a long time.
At 320K it got a slight rod knock on start up, caused by a Holley 650 that I switched to that was dumping the bowls after shut down, I didn't catch it and washed out the bearings- just swapped cranks/bearings here. Added the 700R4. Found out 3.08 gear, o.d. and 285 70 15s aren't a good match for this engine- lugs in o.d.. The truck is pretty quick at this point, for what it is, the deep 1st gear in the 700 helped a lot to get it moving. Swapped this engine for a little hotter engine I had in the garage-the spare for the Chevelle. The truck engine stays on the engine stand ready the go in as a spare- it spent some time in the Chevelle and another short stint in the truck. Current engine has 9.7:1 c.r. with hyper pistons (yuk), Comp 282S cam, vortec heads, high rise single plane, the rest pretty much the same, exhaust grew to 3". Not the same truck at all at this point. Changed to 3.73 gears, has 275 60 15s now as the 285 70s are impossible to find. Woke it up even more.
Brings us to what I'm doing now. Just finished up installing ladder bars, having to re do exhaust, going to 3" x pipe and rearranging how the exaust was located. Added new headers-still sorting out spark plug issues. Have to modify/fab trans crossmember to run the exhaust the way I want it. X pipe and crossmember are what I'm doing now. Pulling the 700 to finish the mods on it and go through it next. After that, the big block that's in the Chevelle is going in the truck after I get its replacement done (started).
This post is too long already-there's been a lot of other work I've had to do to it over the years, a lot due to me wrecking it twice. Bunch of stuff I did to the tranny- it would take forever to go through all that stuff. All this work and the truck is still a heap of junk.