Team Chevelle banner
  • Hey everyone! Enter your ride HERE to be a part JULY's Ride of the Month Challenge!
1 - 20 of 32 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
My ‘71 Chevelle Malibu has been in the family forever. It’s currently all original, 2 door coupe with a 350 and automatic transmission. Looking to boost the engine and turn it into a 4 speed manual. Not really a gear head but I’m learning. Looking for the best option to turn this 350 into a fun run about with some get up and go. It’s only got 95k miles on it so feel like a rebuild is a better option than dropping a crate engine in it. After reading lots of posts I’ve only gotten more confused with the multitude of options that are out there. Would love to hear what you guys think is the best set up/direction to go. Thanks in advance for any input. I posted a few pics of her in the intro section.
 

·
Registered
Joined
·
10,465 Posts
The best place to start is by figuring out what you want from the car. Do you want a car that is basically a cruiser with more power than stock that has a bit of a lopey idle, to take to the track or something in between? This is the most important thing you can do, if you miss the mark in either direction you won’t be happy with the finished product. Do you want headers or stock exhaust manifolds, stock heads or aftermarket. What’s your budget including parts, machine work, assembly and installation. Don’t forget to factor in the smaller parts that go along with a rebuild, but aren’t strictly part of the engine.
 

·
Premium Member
Joined
·
1,104 Posts
Like Steve said, figure out what you want. My 71 was a 2spd 307. Then I put a 350/TH350 in it only to pull them out right after and put in a LQ9(6.0) with a T56/6speed in it. If you want simple, you can do the basic 350 stuff and throw a cam in it. Things add up fast.
 
  • Like
Reactions: Steve R

·
Registered
Joined
·
10 Posts
Discussion Starter · #5 ·
What’s a budget? Aren’t cars like women....they take it all? I’d be happy around $3,500 but think $5k is more reasonable which means I’ll end up spending $7,500 and saying crap why’d I do that? She just feels tired currently and the tranny is slipping on a more regular basis so feel like it’s time to put some life back in her. I don’t see myself taking her to the track but I’d like to be able to open it up and know I’ve still got more. And since I want to add more power I figure now is the time to convert the tranny to a manual. But with all the different setups out there I just don’t know where to focus.
 

·
Registered
Joined
·
10,465 Posts
What’s a budget? Aren’t cars like women....they take it all? I’d be happy around $3,500 but think $5k is more reasonable which means I’ll end up spending $7,500 and saying crap why’d I do that? She just feels tired currently and the tranny is slipping on a more regular basis so feel like it’s time to put some life back in her. I don’t see myself taking her to the track but I’d like to be able to open it up and know I’ve still got more. And since I want to add more power I figure now is the time to convert the tranny to a manual. But with all the different setups out there I just don’t know where to focus.
Your budget is tight. I’d be surprised if the transmission swap doesn’t eat close to $2,500 of your budget by the time it leaves the shop. A good transmission plus the bellhousing, clutch, flywheel, clutch linkage, shifter, transmission hump and possible new carpet adds up fast. An engine rebuild, even with just a few performance upgrades can get out of hand quickly, especially when you add in labor. It’s good you know what you want. I’d talk to your mechanic and hash out a plan and do some research before spending any money. That will be the key at keeping costs down. Know exactly what you are buying when it comes to the transmission, do your research, pickings can be slim and expensive in the Bay Area.

Steve R
 

·
Lifetime Founding Member
Joined
·
14,713 Posts
On the engine do you want the stock original 350 4 bbl look or the "aftermarket" look?
 

·
Premium Member
Joined
·
11,527 Posts
My opinion on the engine.

If the bearings are still good, I would research what a jump to a Felpro 1094 heads yields in compression ratio then get a cam that works with that compression and a set of 195, 2.02 aftermarket aluminium heads. Stay with a flat tappet for money sake.

If you need a total rebuild, I vote to get a 383 rotating assembly and the same heads mentioned above.
 

·
Registered
Joined
·
523 Posts
I've done mine in stages over time to soften the blow $$. Started with a similar setup - 350/TH350 and 2.73 rearend. Changed rearend to 3.73 knowing my next step was a 200R4. This by itself made a tired 350 feel like a new engine. Now I've got a crate engine in the garage waiting for assembly as the final phase of the drive train. I didn't want anything too radical - just a street cruiser that will respond when you put your foot into it - similar to what it sounds like you're looking for.

If you can't afford everything you want together, you may be able to similarly do it in logical stages and be able to drive and have fun in between.

jim
 

·
Premium Member
Joined
·
3,717 Posts
My totally biased opinion is as follows: Two Step It.

Step 1: ditch the manual tranny b/c cash is tight. instead spend 1500 or so on a new TH-350. Keep the stock converter....for now. Have your carb and distributor professionally tuned on a dyno. 200-500 bucks more. Do any other basic maintenance that is needed.

Step 2: Save up about 7K or so. Then build a 383 like mine, get a custom converter from a place like Edge, and enjoy all of your low 12 second passes while being a totally mellow cruiser.
 

·
Premium Member
Joined
·
234 Posts
My opinion - YRMV!

If you are looking at a rebuild, do not even bother with the stock heads unless you want the stock look. On a tight budget Summit has their own replacement cast iron head with 2.02/1.6 valves and 72cc chambers - with a flattop piston that would give you about 9.3:1 compression and the heads are the updated fast burn chambers with 165cc intake runners.

For pistons I would go with a flattop Hypereutectic (again Summit has their house brand) with the stock crank and stock rods - freshened up of course. Not saying the 350 is the only game in town, but they can make a good street engine.

For a cam, I would recommend you contact the manufacture (Comp Cams, Isky, Engle or what ever brand you would like to use) and discuss what you are looking for in performance. the right cam with the above heads and pistons can easily make 350 - 400 HP. The tech staff can help you pick the cam that best suites you goals.

If your budget were not tight, a 383 is a great alternative. You would have areas in the block that would have to be clearanced as well as the rods. Pistons are a little more than 350 pistons plus the cost of a crank (there is cost in freshening up the old crank). What ever route you end up going, the best money spent is in the heads, it will not matter what cam you choose if the heads cannot breath enough - TBI 350's and 454's are proof of this!
 

·
Registered
Joined
·
248 Posts
I would start with headers and good freeflowing mufflers, my experience with small block engines indicates the cam and timing chain are seriously
degraded with your mileage, just a mild cam and new timing set will provide a lot of snap, unless you can find a used trans I agree changing to manual will probably cost $ 2500 but it's much more fun to drive
 

·
Registered
Joined
·
180 Posts
My opinion...If its an all original numbers matching car, personally I would keep that aspect intact. Get the transmission rebuilt, crisping up the shifts. New converter (stock, or just a smidge above, nothing crazy). Rebuild the engine with minor modifications. If the cylinder bores are good you can just cut the ridge and hone the cylinders with new rings, or go .030 over with a new set of pistons/rings. Get the heads/valves done with new guides that'll work on today's pump gas and new springs to match a mild cam. A kit like the K12-238-2 from Competition Cams would include a good cam for your application and includes springs, lifters, timing gears/chain, seals, and spring retainers and will be under $350. Upgrade the distributor to electronic ignition.

Now here is the only thing I would change. Edelbrock Performer manifold, a Holley 600 with vacuum secondaries (or if you already have a 4bbl Q-Jet, get that rebuilt and tuned), and a set of headers with dual exhaust. (Keep ALL the original parts you replace and store them away for safe keeping, and if the stock exhaust is good don't let some butcher hack it up and scrap it, keep that too)

Make sure to dial in (degree) the cam and gasket match the intake ports on the heads and intake.

You'll have a basically unmolested "numbers matching" Malibu (getting harder to find) that you'll be able to drive anywhere (assuming the chassis/suspension is all good to go) and still have some lead footed fun for probably WAY under your budget.

Again, my opinion.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #15 ·
Hey all, loving the information and opinions! Thank you. I am torn because I like the all original aspect of it but I also see potential to make it a lot more fun to drive. I am agreeing with everybody that’s said go in steps. So I think I’ll be holding off on the transmission and focus the money on the engine this phase. Time to research up on the information you’ve all given me so I can ask some educated questions. Great forum here, and excited to get this project rolling once I get the direction dialed in.
 

·
Registered
Joined
·
4,691 Posts
here's what you should do. new flat tappet hyd cam 270advertised duration on 108 lsa isky makes one thats close. new vortec cyl heads. hei distributor edelbrock performer and a 3310 holley. if its an original q jet car keep the carb.either keep the manifolds and go dual 2 1/2 exhaust or add 1 5/8 headers for a little more performance. some basic tuning and this thing will run great and be reliable. if you dont plan on driving much on the highway i would go 373 gears and rebuild the 350 with a good convertor. if you wanna drive on the highway go 200 or 700 r4 overdrive or if you want a manual look for a t56 out of an ls1 camaro. if you stick with a 350 this plan will cost less than 5k. check and rebuild the brakes with front disks and the front end if needed
 

·
Premium Member
Joined
·
9,036 Posts
You said its been in your family since new,that's great.Is it a 2 bbl or a 4 bbl 350.It makes a difference in what you want to do with it. ----Copied & Pasted below ---
2 BBL would be the :
L65
The 2bbl carburetor 145 hp (108 kW) version of the LM1 350. It was produced until the 1976 model year. It had 255 lb/ft (346nm) of torque.

4 BBL would be the:
L48
Years: 1967–1980

The L48 is the original 350 cu in (5.7 L), solely available for 1967 in the Super Sport (SS) version of Camaro (1967-up) or Chevy II/Nova in 1968-1979. In 1969 it was used in almost all car lines; Camaros, Caprices, Impalas, El Caminos, Chevelles & Novas. The 1969 L48s use a hydraulic cam, 4bbl Quadrajet carburetor, cast pistons, 4-bolt main casting number 010 Blocks & casting number 041 or 186 heads. Power output was 300 hp (224 kW) SAE and 380 lb⋅ft (515 N⋅m) torque. Compression ratio was 10.25:1. The compression ratio of the L48 was lowered to 8.5:1 in 1971.

In 1972 the L48 (4bbl V8) option for the Nova was part of the SS Package. This is indicated by the fifth digit in the VIN being a "K". 1972 was the only year the SS package could be verified by the VIN.

The L48 engine was exported to Australia, where it appeared in the Holden Monaro from 1969 through 1974, and in the Statesman (automobile) from 1971 through 1974. Towards the end of the HQ series in 1973-74, due to US emissions regulations, the performance of these engines had dropped to the same or lower than Holden's locally manufactured 308 cu in (5.0 L) V8, which was not yet subject to similar regulations, so Holden's discontinued using the engine.

The L48 V8 was the standard engine in the 1975–1980 Chevrolet Corvette. The L48 V8 Corvette engine produced 165 hp (123 kW) in 1975. Power increased to 180 hp (134 kW) in 1976 and stayed the same in 1977. The 1978 saw 175 hp (130 kW) for California or high altitude areas and 185 hp (138 kW) for everywhere else. Power increased to 195 hp (145 kW) in 1979 and decreased to 190 hp (142 kW) in 1980.
C&P is done.

The best part is if its a 4 bbl it is probably a 4 bolt main making it an excellent basis for a strong running rebuild.If you're able to do most of the R & R yourself then $4K would probably get it done using good parts.Also if it is an L48, those engines almost always got 12 bolt rears from the factory.
 

·
Premium Member
Joined
·
5,209 Posts
Suggestions, if you have a good running engine, upgrade the drivetrain first. Going to an overdrive trans, either stick or automatic will transform the car unbelievably! The stick will make it fun to drive and the od will allow you to drive places at normal rpms and decent highway speeds. Then figure out what you want in the engine. Maybe even find a block or another engine to build and keep your numbers matching unit.

Do a TKO and add a 373 posi axle and you will be amazed!

There will be a lot of detail changes to go from a stock 350 to an aftermarket setup. Carb, headers, intake, etc will all require changes to choke stuff, cold start stuff, the head pipes, etc. I have a stockish rebuilt 350 in my 66, with a total of $1200 in a rebuild several years ago. It has some stock 70s heads, with screw in studs, and a small Comp cam. (not part of the $1200) Its fun but no powerhouse. For the money to do it again, I would not spend a dime on stock heads. I would go directly to a set of aftermarket aluminum heads with a matching intake, carb and cam. Something like an Edelbrock top end kit would be the best step.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #19 ·
Been taking in all the great info and researching whenever I get a chance. Here’s where I’m at.

Figure I’ll start at the rear end up want to go with Posi 3.73. So I look back under the car and she’s only got a 10 bolt and looks like it’s only a 7.5” and I’m not sure of what the current gears are but looks like no matter what’s in there I won’t be able to upgrade it to support the engine mods I want. At least from the sounds of it at a cost that is worth it and have any reliability. So what should I look for? A 12 bolt? 8.5 10 bolt? Or something completely different?

Moving to the transmission, after doing some research I’m thinking my converter is what’s causing my current transmission woes so plan on having the transmission rebuilt with a new converter put in. And from what I gather it’s worth having that beefed up a bit compared to stock.

As for the engine I want to try and keep the matching numbers so going to do a rebuild on that but thinking new after market heads, cam, headers and a 4 BBL carb. and need to start researching more on that to see what will work best with the rear end and tranny. It currently only has a 2BBL so will be replacing that.

As for the end purpose of the car it will mainly be a run around car so want it to be a quick get up and go. Will have limited freeway driving, 15 minutes to work or if I want to take it on a weekend jaunt wouldn’t see more than an hour of the open road. I’d like to do it right the first time which means I’m already going to be pushing out that budget.

Please let me know if I’m off track on my thought process, once again not a gear head and in all new territory here. Thanks.
 

·
Lifetime Founding Member
Joined
·
14,713 Posts
12 bolt diffs are pretty pricey nowadays and most need a rebuild on top of it. 8.5's can be hard to find and expensive to rebuild. If your diff is stock it's probably an 8.2 ten bolt. It would be strong enough for what you're doing, especially with stronger aftermarket axles, unless you put sticky tires on it.
 
1 - 20 of 32 Posts
Top