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