Hey guys,
I've just got a 351w out of a 89 to replace the 302 in my 85 F150. Wanna do a few things to it before I put it in the truck cuz I'm trying to turn my truck into a street rod. It's got GT40 iron heads, edelbrock performer intake manifold and 750 cfm carb. Please shoot me with some good idea to do with the motor!
Thanks!

 

Put a better cam in it(comp 35-238-3), a better intake(Weiend Stealth) and a better carb.. 600 vac secondary.

 

Do you think I should go with a new head? I really want an aluminum one. Do you think it's a good thing to make it a dual-carb setup or is it a waste of money on the small block 351? Any suggestions on supercharge or not?

 

Supercharger on a carbed motor.. Good luck with that. This motor is already making double the HP your old 302 was but if you want aluminum heads go for it, the TFS fast as cast are a great deal right now for example.

 

If you go with aluminum heads I may be interested in your GT40 heads (and then Conan can tell me what cam to get).

 

With these items along with shorty headers and a free flowing single exhaust what type of horsepower/torque would one be looking at? Assuming the rest of the engine is a stock rebuild, and would it be a good combination for moderate pulling power and decent fuel economy?

 

300-320 hp and 380-400tq(with headers).
Compared to the 5slow it'll be harder on fuel in the city but out on the highway at reasonable speeds it'll do better. As far as towing goes you'll swear somebody stuffed a big block under the hood while you weren't looking, you're gonna be amazed at the power this thing has compared to what it's replacing.

 

Horsepower equals how fast you hit the wall, torque equals how far you drag the wall with you, in a big heavy vehicle like a truck or van you want both torque and hp but you want to focus on max torque and let the horsepower fall where it may, keep air velocity high all the through the engine and pay special attention to the exhaust, a properly designed exhaust will do 2 things, it will act as the 5th cycle of a 4-stroke motor and help to scavenge burnt gases from the cylinder which equals a less contaminated A/F mixture in the chamber come burn time, the other benefit to a properly designed exhaust is both a increase in torque and horsepower, all the tricks to tuning your combo are the same as any other hp engine, once the headers are installed and exhaust pipes have been installed take a can of paint and spray the exhaust pipe from the collector back about 2 feet, fire it up and rev it a couple times, now look and find where the paint stopped burning and that is the exact spot you want to add the crossover pipe.. shutup george......

 

What would I need to do to put 302 heads on my 351 Windsor??

 

enlarge the head-bolt holes from 7/16 to 1/2"..

 

Does it give me more power and torque?

 

It can depending on the difference in combustion chamber size between the two heads and any differences in flow numbers, you have to put the heads next to each on paper and list the differences in intake runner cfm, I/E flow ratio, CC size, valve diameter, all these factors come into play but i believe the 351 has E7 heads on it and are most likely superior to any E5 stock heads built on a small displacement 302, the 351 heads will have bigger valves and bigger intake/exhaust runners than a 302 so it doesn't seem like a good idea to swap 302 heads onto a 351 UNLESS they are proven to flow better numbers than the 351 heads, there is no other single modification you can make to an engine to gain more horsepower and torque than replacing the cylinder heads but you have to know what you're doing and combine the heads with a camshaft designed to complement the I/E flow ratio... good luck my friend..

 

WRONG... 302/351 heads after like 82 are all the same.. no difference.. so swapping them is a waste of time.. Go GT40 or Aftermarket...

Aftermarket Trick flows are the way to go..

 

Trick Flow makes some very good heads but before you start telling people how wrong they are i would strongly suggest you obtain a 302 head and a 351 head and lay them next to each other and tell me again how they are "all the same"..

 

From about '78 on these two motors wore the same heads(same casting number, same chamber and port volume, same valve sizes) so there is nothing to be gained with this swap on a "late model" motor. Back in the '60s and early '70s Ford made different heads for these two motors with the 351 heads getting bigger valves and ports but none of these heads got hardened valve seats and many also had a less than desirable pressed-in rocker stud design so making them suitable for modern lead free gasolines and performance cams can be cost prohibitive given the marginal gains that will be realized compared to what you can get with aftermarket heads.

In general none of the stock ford heads flow that well, they will produce decent power on a 302 but they're all undersized for a 351 and will limit Tq and Hp potential. The late model iron GT40 variants were the best of the bunch and would be a good choice for a low rpm torque biased 351 build, as gman suggested with the right cam and exhaust system this motor can deliver a surprising amount of grunt, you just got to get that "bigger is better" idea out of your head and think high air velocity instead.