Best 5.8 donor?

68keyblr · Jun 22, 2006

I'd like to build up a 393 stroker in my '68, but I want to go EFI. Has anyone done this? What is the best 5.8 donor car out there?

D.Hearne · Jun 22, 2006

Not donor car, you want a donor truck or van. I don't believe any of the car 5.8's came with EFI, unless it was a throttle body system. The 94-up 5.8's had roller blocks.

68keyblr · Jun 22, 2006

D.Hearne said:
Not donor car, you want a donor truck or van. I don't believe any of the car 5.8's came with EFI, unless it was a throttle body system. The 94-up 5.8's had roller blocks.

I thought Crown Vics might have come with 5.8 EFI

Do you know if the 5.8 EFI computer is the same as the 5.0? (EEC-IV)

Thanks!

streetgrande69 · Jun 22, 2006

it is a speed density based efi system and the intake for it is huge and most likly won't fit in your car under the hood.

your beat bet is to get mustang stuff with the maf and just get the 351w swap stuff for the car....upper-lower masaie intake. you'll probably need larger injector

most of this is 5.0 related but i think if you don't look at the chasies stuff and payattention to the motor only stuff youd get a decent 5.8 with a donor 5.0 car.
http://www.fast351.com/tech/351w.htm

D.Hearne · Jun 22, 2006

Very few Crown Vics came with a 351. But you might get lucky. As far as I've heard most of the 351 Vics were cop cars and those had carbs. You'd have an easier time sourcing one from a pickup or van.

D.Hearne · Jun 22, 2006

streetgrande69 said:
it is a speed density based efi system and the intake for it is huge and most likly won't fit in your car under the hood.

your beat bet is to get mustang stuff with the maf and just get the 351w swap stuff for the car....upper-lower masaie intake. you'll probably need larger injector

here is an excertfrom a 5.0 forum
FACTS: What you need to know/consider when you swap a 351W into a Fox3 platform chassis:

The 351 block is very similar to the 302. That means that almost all parts swap between a 302 and a 351. This includes: Heads, cam, lifters, timing chain, timing chain cover, water pump, engine mounts, and all sorts of other stuff. The bellhousing bolt pattern is the same as a 302, so all trannies that bolt to a 302 will bolt to a 351. However, there are some differences in the 351 that necessitate new parts:

1) The oil pan is different. Motorsports carries one. You can also get an oil pan of of an early eighties LTD Crown Vic. If you go the junkyard route, remember you also need a oil pan pickup tube, and a special main bolt that the pickup attaches to. The FMS pan is a pretty good deal, and if you shop around, you can get one for under $100, which comes with the dipstick, bolt, and pickup tube.

2) The internal balance of a 351W is the same as pre-81 302's (28.2 oz). The 5.0 HO has a 50 oz. unbalance, which means you cannot use the flexplate/flywheel or the harmanic balancer off of an HO engine. You have to get the correct pieces from a dealer/junkyard.

3) The deck height is higher, which means you need a different intake, since the 351W intake is wider. A 5.0 Upper will bolt to a 351W lower.

4) Also, a higher deck height means that the accessory bracket will need to be replaced. FMS sells the new bracket for about $50.

5) The higher deck height means the headers sit up higher than in a 302 powered Mustang. A special set is required for a 351.

6) A 351W will in all likelyhood not clear the stock hood. You will need a cowl hood for your car.

7) The distributor has a fatter shaft. You can obtain one from a 351W powered FI truck (if you are using FI) or any late 70's/early 80's car using the 351W and a Duraspark system if you are going to build a non-efi car.

Those are the major differences. As you can see, for about $1000 you can put a 351W in your Mustang. This is cheaper than a stroker, plus you wind up with a more reliable engine.

Tips: There are several things to look out for to ensure that your swap to a 351W is easier and more successful. They are as follows:

1) A high volume oil pump WILL NOT clear the FMS pan. If you want to run an HV pump, you must either modify the pan, or buy a Canton or similar pan, for many dollars more. The modifications just include cutting down the front drain bolt, and welding on a corner to the pan to clear the pump housing.

2) Get new motor mounts. If your mounts are questionable already, the additional weight of the 351W will make them fail in a hurry. I recommend the 87-93 convertable mounts, which will work in any 79-93 Mustang.

http://www.fast351.com/tech/351w.htm

The Vic pan won't fit an early Stang anyway, but is is a prize that can be sold on ebay. A 351 will fit under the hood of an early Stang, 69's and 70's had em. Lots have been swapped into 65-68's.

68keyblr · Jun 22, 2006

Thanks for the good info!

streetgrande69 · Jun 22, 2006

D.Hearne said:
The Vic pan won't fit an early Stang anyway, but is is a rize that can be sold on ebay. A 351 will fit under the hood of an early Stang, 69's and 70's had em. Lots have been swapped into 65-68's.

thats why i said he'd need to diregard the chasis info. i also know that 351w fit....but not with the stock efi intakes....most likley

69Rcode_Mach1 · Jun 22, 2006

The later bronco's came with EFI 5.8's if I am not mistaken. I don't know if they are speed density or mass air flow though.

bnickel · Jun 23, 2006

early 90's crown vics could be had with a fuelie 351w and i believe mass air as well. i've seen several of them around town here but i do believe that they were all ex-cop cars, also i'm not 100% positive they were mass air but relatively so, again this would be a cop car only option i believe

96 DOHC Cobra · Jun 23, 2006

91 or 92 was the last year Ford used the 351W in the Crown Vics, and they were carbed. The only EFI 351Ws from Ford (aside from the 95 Cobra "R") were the 86 to 97 Trucks, Vans, and Broncos.
Think carefully about what you want to do, and choose your donor carefully. The 94-97 blocks are "roller-ready" but are thinner castings and considered not as reliable as the early blocks. The early blocks (69-74) are thicker and usually prefered, but finding one that's still standard bore would be tough by now. There are aftermarket blocks available that give you a combination of the best of both worlds, but cost Mucho $$$. Think wisely before deciding.

D.Hearne · Jun 23, 2006

Where'd you hear that about the 94-97's being thinner ? That doesn't seem to jive with the late 5.0 castings, those are thicker (E7TE and E7SE blocks) If anything the casting quality got better to allow them to use less iron.

bnickel · Jun 23, 2006

also after 84 all crown vics were fuel injected and 86 and later are all sefi and not tbi equipped.

up until 91 the 351's were vin code G in the crown vic

1970 slantroof · Jun 26, 2006

One of the car mags just did a build on a 302 or 351 and they chose a 70's block because they said it was stronger than the 5.0 version. I will try to find the article.
Howard

bnickel · Jun 26, 2006

1970 slantroof said:
One of the car mags just did a build on a 302 or 351 and they chose a 70's block because they said it was stronger than the 5.0 version. I will try to find the article.
Howard

the earlier blocks are stronger but not that much stronger and it really only matters when you are building really high hp motors. under 450 hp and any stock block is fine. even stock 5.0 short blocks are good for 500-550 hp and more with a supercharger. when you start getting past 550-600 hp the stock blocks start to split especially with nitrous motors. the earlier blocks are only good for maybe another 150-200 hp once you get to the ragged edge.

for a fairly mild street motor under 400-450 hp i'd rather use a late model roller block

65fastback2+2 · Jun 26, 2006

i wanna know this too, cuz im wanting to do a supercharged 393 stroker to my stang....i dunno to go roller, efi, carbed, old block, etc.

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