Thread: pre '86 SBC 350 Conversion to EFI and cam selection

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Hey guys, Ive got my eye set on the Edelbrock Pro-Flo 4 EFI system to put on my pre '86 SBC 350. Im trying to figure out what i would need to do in order to make this work, and am trying to find a good cam selection to partner with it. Any and all advice would be greatly appreciated. Thanks in advance.

Welcome aboard. For a blanket statement of pre- 86 SBC 350.. I'd say why not call Edelbrock Tech? They built it and should know their product. I'm sure they'll ask the same questions I'm about to.. LOL

Is this a street car? Street & Strip? Or daily driver? Auto or Manual trans? Do you know the "stall speed" if auto? What gear ratio in rear axle? What size tires? I know it's a lot of questions but those answers will be needed.

If they ask you what color the battery is... then they've gone to far! LOL

Its a 1980 chevy c10, that im wanting to be a daily driver again but have more power than stock. tires size is 255/70r/15. I dont know stall speed. It has a TH350 behind it but havent dug into the trans to know. and as far as gear ratios go, i havent messed with those either. Ive had the truck since i was 16 and drove it everyday to and from school. now, yes i am only 21 now. but still, its been 4 years and i have no idea what im doing still..

Welcome to CHR!

At 21 you’re getting in at the “beginning” of your adult life and hopefully, this will be not only a hobby but a real source of education and enjoyment. For the most part, the folks here at CHR want to help in both areas. We’ve built collectively hundreds of engines/cars/trucks – you name it, we’ve probably done it!

Your 1980 C-10 is probably powered by the venerable LS-9 350 engine. You have 165-175 horsepower, depending on where the truck was originally sold, and a TH350 with 2.52, 1.52, 1.00:1 ratios and in all likelihood, a 3.73:1 limited slip differential. All basic stuff and these things ran for ever. It’s not uncommon to see them with 200K miles on the odometer and if they have had regular maintenance, all eight cylinders will still squeeze 100PSI+ on a compression test.

I think your idea of EFI is a great plan. However; if I were you and starting on a 41 year old truck as my first big project, I would pull the engine and do a total rebuild. “Yikes, you may say”, “that sounds like a lot of time and money!” and you would be right. There are some cheaper ways to get the EFI up and running but there are no inexpensive ways to do this the correctly. If you install the EFI (even as an Edelbrock kit) and put an aftermarket cam in you’ll be sorely disappointed and I can almost guarantee you will be dissatisfied with the overall results. I say this because it will be way too easy to do just that (EFI and cam) and then you’ll want to stomp on the go fast pedal way too often and you will find out that those 41 year old rings are beyond their prime. You’ll also wish you had installed a roller cam (instead of a flat tappet replacement) and new heads as your current 8.2:1 compression ratio will be compromised along with the tired rings and valves will leak – increasing oil consumption and generally degraded performance. It will happen – trust me, and you’ll be thinking you dropped $2K plus and are not really happy with the overall results.

Not to be an absolute buzz kill, there are a couple ways to approach this. The cleanest and quickest option would be to buy a turn-key 350 or 383 roller engine that’s fuel injected. It will run you $3,500 - $6K, depending on how much horsepower you want and how close to a complete engine you buy. Most come with a 36,000 mile 3 year warranty. Not a bad deal if you plan to keep your truck for the foreseeable future. Key here is that you buy a roller cam engine that’s ready to run out of the crate and even the basic offerings will give you 150 more horsepower than you now have. Bear in mind if you get to the 400 horsepower range, the TH350 and rear end will need attention as well.

If you’re set on keeping your engine and building it, you can still make a lot more horsepower and have fun learning how to do this in the process. Rebuilding the block with the stock crank, good quality .030 over pistons, (a -10cc flat top would be a good choice) and a set of AFR 195 aluminum heads with Fel-Pro 1003 head gaskets can get you in the 9 - 9.5:1 compression ratio and will allow you to easily run pump gas. Have the block cleaned and magnifluxed (no need to build a cracked block) and decked to 9.010”. You can have your machinist install cam bearings and prep your block to accept a roller cam retrofit (proper timing set, hardened distributer gear (use stock HEI distributor), front cover with roller provision) and set the EFI manifold and injection system atop a good healthy block/heads with tight rings and valves and enjoy north of 300 horsepower in a very well behaved package all the while keeping the stock TH350 and rear end. This route will still set you back close to $4,000 with machining cost and new parts but if you enjoy the process, it’s a lot of fun.

I’m sure others will chime in – let us know what you’re thoughts are after digesting all this information.

Once again, welcome to CHR!
Glenn

Welcome! Glenn has given you great advice and some options, and while you may think his costs are way out of line he's been doing this stuff for a long time, has the tools & experience, and tells it true.

At 21 I expect that your assortment of tools is pretty basic, so rebuilding your engine yourself is going to present some challenges that you need to consider. Engine hoist/Cherry picker - you can buy one at Harbor Freight (HF) but then you've got to store it so borrowing one or renting one makes sense. Once your engine is pulled you have no truck, so you need a way to get it back - gotta have a plan. Engine stand? HF again, or maybe a buddy has one you can borrow for a month or two? A roller dolly is nice for the tranny - cheap at HF but lots of cheap $$ adds up fast. Do you have a safe & secure place to work where you can park your truck and have your disassembled engine for a couple of months without anyone complaining? Even if you live with Mom & Dad their patience may wear thin after a week or two, especially if the neighbors, or worse the HOA are calling wondering why the truck hasn't moved in so long.... Live in an apartment? Even worse! Tools, let's cut to the chase and say you probably need to add $500 or (likely) more to your budget for things you don't have but will need for a DIY rebuild.

I believe that you'll be way, way ahead of the game if you go the crate engine route, or perhaps a salvage takeout package from a later model that gives you engine, tranny, ECU and harness from a reputable supplier. Most important is to take time to really think through everything, decide on your path, then plan, plan, plan. Once you have your plan in place commit that you're not going to deviate when your buddy says, "Hey, how about we...." because changes are budget busters!

It's great that you're wanting to freshen up the truck, especially since it's been yours since 16! Take a look at this thread that Glenn updated not long ago - 1971 c-10 How about a picture or two of the truck as it is now?

Glad you're here, looking forward to following your project no matter which way you go!

No matter which way you decide to go I sure hope you stick around, we could surely use some new and younger folks. Why don't you start a thread to show your progress? Anyway, good luck on whatever you decide.

I'd suggest the late model takeout of complete engine and tranny eguipped with accessories and belt drive and the computer and wiring harness-------they are roller cammed, very good milage, plus the a/c compressor is for the newest # freon , you can get low milage packages out of suvs, trucks, camaros-----for under $2000

Originally Posted by seymour6968

Hey guys, Any and all advice would be greatly appreciated. Thanks in advance.

Did you think you'd get so many different options / opinions / questions / thoughts?

LOL, Hope you find the conversation encouraging!

Guys I cant thank y'all enough. Your responses have been more than encouraging, they've been enlightening and and helpful in my decision. As far as my tool range and where I'll be doing it, a family friend of mine is helping me do this and has every tool there is to have when doing this work and has the shop/lift to do it in. As far as parts and process, we are going to be rebuilding the engine completely and if-need-be the transmission as well. replacing the heads and his original thought to do was TBI, but I feel as though I would be happier with EFI. during the rebuild process we will obviously be going through and resealing everything and putting new rings on the pistons. I am gonna have to have the block machined for sure though. And, as far as cam selection goes, I was only really considering a roller cam anyways, so that definitely works out. Again, I greatly appreciate y'alls replies! Cant thank y'all enough! I'll be posting in here my progress once I start in on the project of it. I've had it since I was 16 as my first vehicle and want to be able to one day hand it down to my son who is about to be 3 years old. I'm overjoyed to be able to start getting the truck in the condition to hopefully be able to do just that one day.

Keep us posted on your progress

Originally Posted by seymour6968

Guys I cant thank y'all enough. Your responses have been more than encouraging, they've been enlightening and and helpful in my decision. and his original thought to do was TBI, but I feel as though I would be happier with EFI. Again, I greatly appreciate y'alls replies! Cant thank y'all enough! I'll be posting in here my progress once I start in on the project of it. I've had it since I was 16 as my first vehicle and want to be able to one day hand it down to my son who is about to be 3 years old. I'm overjoyed to be able to start getting the truck in the condition to hopefully be able to do just that one day.

Perhaps a setup like the Holley EFI is what either you or your friend was referencing? It would be a good choice imo too. Glad the group was able to help.. We enjoy that as much as you.

The fact that you've got a family friend with tools and a shop is a game changer, plus it sounds like he's experienced with rebuilding, another big plus.
I hadn't looked at the ProFlo 4 but it looks like a great choice. I have one of the original ten ProFlo XT's that they made for the small block Ford on my 347 stroker, and I see a lot of advantages to the newer one. In fact I've thought about talking to Edelbrock about what might be required to upgrade my old XT to a new ECM that's self learn, as mine is programmed on the laptop. Once done it's OK, but their self learn system continues to tweak the tune as you drive. The advantage that I see with the ProFlo 4 is that it includes an intake designed for the system where others are more carb replacements that bolt atop your manifold. The 4 seems to be more of a complete package with the intake, EFI, electronic distributor all packaged together. I'd go for it!
With this new info perhaps Glenn will chime in with some ideas on the cam choice. He's usually got some really good ideas and explains things well.

Hey Roger, so I actually called edelbrock today and had a conversation with the Pro-Flo technicians on the phone and was able to get the info on how to set it up. It's a very simple and easy kit to use. If you're running a mechanical pump you'll need the universal sump kit that runs a line back to the tank. But that's really everything extra you would need. It comes with an ecm and wiring harness that work and control the unit. as well as the distributor. So it comes with everything you would need and have to make very minimal(if any) changes to be able to run it. I am very highly considering getting one for myself after talking to the guys over at edelbrock. If you wanna give 'em a call, they're super helpful!

You won't find many mechanical HIGH pressure fuel pumps for street applications-----

How much $?