I have an old 1993 351w with 180,000 miles on it. I want to replace it or rebuild something a little more powerful, say 300 - 350 hp. This is a semi- daily driver, with some towing. No racing or anything.

It is carbureted in an older pickup. The only thing on it that isn't stock is an eldelbrock performer intake and a holley 650 with mechanical secondaries.

What is the easiest/least expensive way to get it like new with 300+ hp?


I have experience replacing and working on motors but no experience building them. I have basic mechanics tools but no machine tools.

Thanks,
Jake

 

You'll need to set a budget first, you can count on spending $1000-1500 rebuilding the bottom end regardless what pistons or cam you select, and you could easily spend $500 rebuilding the heads but since they are the major choke point and would need professional porting to break 300hp I suggest you look for some lightly used aftermarket heads.

 

I figured on getting a stock short block rebuild, a cam and a set of heads. Just wanting to know what cam and heads are the best bang for the buck and if any could make 300 hp with the carb and intake i already have.

 

To be clear, is your truck EFI or carburated ?

300hp out of a stock headed 351 is achievable. First check your block casting number to see if it is roller cam compatible.

Attention to detail is the key. A little more compression with good intake and exhaust. Over 9/1 but bellow 10 and if your truck is roller cam compatible I would look for a H.O. cam from a Mustang. Good machine work with high pressure oil pump(not HV), MPG windage tray, cam degreed on a 112* centerline, 1.7 roller rockers, new valve springs.

How well your truck runs depends on the stuff you use to support your motor.

 

The Performer RPM intake is a much better piece for hp. If you get a nice set of heads and a better cam it will hold the engine back above 5,000. But since you're not racing no worries, eh? I'm not a big fan of mechanical secondary carbs on street-driven trucks.

Pretty much any commonly available aftermarket aluminum heads should be fine. Bang for the buck wise it's hard to beat Comp Cams' K-kits - pretty cheap and they come with all the matched parts (springs, lifters, timing gears, etc.) needed.

 

id say go on ebay and get a set of gt40 heads, not gt40p heads, get a simlpe cam, like say call up a cam manufacturer and ask them which would be proper for you engine and needs, the stock air intake is fine till about 350hp, but an upgraded manifold wont hurt and should bring that baby to life, 1.7 roller rockers are a good idea to boost power but you need the cams to be compatible with it, getting new and higher quailty injectors will help alot or atleast clean out your old ones, and if you can find the computer senor thingy that tunes your efi to handle the new power mods would really help too. big thing is headers and a new exhaust set up because that robs power big time, either 2.5in duals or a 3in single pipe are the best ways to go, not to mention a simple cleaning like new filters and removing the grime built up over the years

 

Guys he already mentioned its got a carb, so no need to ask if it is again, also no need for new injectors.

I think your intake and 650 w/mechanicals are fine. I would take the engine to a good, reputable engine rebuilder. I would ask how much they would charge to build it stock except for a new cam.

Someone correct me because it's been a while, but wouldn't 107 degree cam be better than say a 110 or 112? Doesn't the 110 and higher cam start putting the most power up in the higher revving zones? Unless he's racing he still wants power down low, it's still a truck right.

If your engine shop is good they can tell you exactly what cam to put in the engine, so then you'll get your power around 2,000 RPM's not 4,000 RPM's and above. You should get a mildly aggressive lift and duration but don't worry about a loss of vacuum pressure, you've got the carb with mechanical secondaries.

If your heads are in good shape just have them ground and ported, and ask for the biggest valves to be put back in. I don't know the 93 series at all, but your machine shop can tell you, and I wouldn't waste money on swirl polished, stainless steel, triple angle valves, ask them for a high quality oversized 3-angle valve.

I keep stating my comments based on you not wanting to waste money or make a race truck. Don't waste money on a windage tray, you're not drag racing trying to shave a few tenths off the time slip are you?

As for the 650 cfm you should be fine. You could put a 750 cfm on it, but you will need to restrict the gas jets down soo much you won't be gaining much. Unless you start forcing air down it's throat a 351 Cu In engine is only going to suck down so much air on it's own, so no need to drown it with fuel. I built a 351w running a 650 carb and was running low 12 seconds in my 1979 Mustang.

Bottom line if you haven't done this already:
Good engine rebuild
Aggressive cam
Stock Heads ground and oversized valves, some port matching if not ported
(a full porting job will cost a few hundred bucks or more)
Oh, and don't forget to upgrade your ignition/coil (nothing crazy just something over stock)

If I were to have another engine in a car that was a 351, and I wanted to build it up, I would scrap it and get a 302. The parts are amazingly cheaper when your all said and done.

 

Got headers?

 

what FORDTUF1 said exactly really, along wit a good cleaning out and new vacuum hoses, headers, and a good air filter