What would be involved in replacing 302 with 347 stroker?

maillemaker · Jan 19, 2026

I have a 1995 Mustang GT convertible. It's bone stock. The motor only gets 7-9 PSI when hot at idle for oil pressure. Probably the bearings are shot. 120K miles.

I am contemplating replacing the motor with a 347 stroker. I want the stock instrument cluster to continue to function.

What is the best way to go about this?

I see a long block here:

Ford Small Block Compatible 347 c.i. Engine - 415 Horsepower - Long Block

BluePrint Engines 302 c.i. small block Ford style crate engine - longblock. Includes 30 month / 50,000 warranty & BPE Dyno Promise. Part #: BP302CT

blueprintengines.com

What upper/lower intake would be good? I have heard a Trick Flow S series.

Would I need bigger injectors?

Would I need a different ECU? How to make the instrument cluster go if so?

96blak54 · Jan 20, 2026

I know im going to beat a dead horse here, but replace with what you have. Its so much more simple and turn a round time to get the car back on the road and enjoying it is very minimal.

I did the same thing. Put a bigger engine in mine and spent to much money. I should have just kept things the same and rolled with it. Also no more power and its still slow

Also, the low oil pressure isnt that uncommon and will take you many more miles. Stepping up to a heavier weight oil might help.

95opal · Jan 20, 2026

maillemaker said:
I have a 1995 Mustang GT convertible. It's bone stock. The motor only gets 7-9 PSI when hot at idle for oil pressure. Probably the bearings are shot. 120K miles.

I am contemplating replacing the motor with a 347 stroker. I want the stock instrument cluster to continue to function.

What is the best way to go about this?

I see a long block here:

Ford Small Block Compatible 347 c.i. Engine - 415 Horsepower - Long Block

BluePrint Engines 302 c.i. small block Ford style crate engine - longblock. Includes 30 month / 50,000 warranty & BPE Dyno Promise. Part #: BP302CT

blueprintengines.com

What upper/lower intake would be good? I have heard a Trick Flow S series.

Would I need bigger injectors?

Would I need a different ECU? How to make the instrument cluster go if so?

How fast will your wallet go? If its a 10k wallet send it. If not stock rebuild.

RAU03MACH · Jan 20, 2026

welcome to the forums
we have all been through this but you will probably hear from members sometimes it's not worth it
i have said this before everyone sees the numbers and jumps in wanting one, without knowing the full details about stroker engines

weendoggy · Jan 20, 2026

1st thing to do is find out if you're under any emission inspection requirements.

maillemaker · Jan 20, 2026

96blak54 said:
I know im going to beat a dead horse here, but replace with what you have. Its so much more simple and turn a round time to get the car back on the road and enjoying it is very minimal.

I did the same thing. Put a bigger engine in mine and spent to much money. I should have just kept things the same and rolled with it. Also no more power and its still slow

Also, the low oil pressure isnt that uncommon and will take you many more miles. Stepping up to a heavier weight oil might help.

Yeah I now run 20W50. Putting in a bottle of STP Oil Treatment also works.

You're probably right. I don't drive it that hard anyway. Also I think you can hit 400 HP in a 302 with better cam, heads, and intake. Probably not necessary to go 347.

maillemaker · Jan 20, 2026

weendoggy said:
1st thing to do is find out if you're under any emission inspection requirements.

Alabama has no inspection requirements whatsoever.

ttocs · Jan 20, 2026

400 hp na takes some cash with a 302. Now add some boost and suddenly it is with in reach.

weendoggy · Jan 21, 2026

maillemaker said:
Alabama has no inspection requirements whatsoever.

Then you can open the can of worms. Going to a stroker isn't the same as stock displacement, given the stock ECU and parameters. This is where the worm can starts. Using a 30yr old ECU to tame a setup that's more...you get the picture. I put a .040 over in a customer Cobra from BP and it's good. Came with a Sniper, but you can get it without.

Mustang5L5 · Jan 21, 2026

96blak54 said:
I did the same thing. Put a bigger engine in mine and spent to much money. I should have just kept things the same and rolled with it. Also no more power and its still slow

Same. At the end of the day, after rebuilding the engine in my Fox and spending lots of money on go-fast parts, and lots of time, and aftermarket ECU and tuning and such....not sure I would do it again.

My fox is actually apart right now, because through tuning I found my fuel system wasn't adequate, so I had to throw more $$ at it. Come spring time, i'll have to retune again so more seat time with a laptop.

When i go into my garage on a nice Sunday, i usually end up driving my stockish SN95 over the Fox. There's something to be said about just having a simple, reliable combo. If i could go back i would have just done a mild 302 (exhaust, camshaft maybe) and enjoyed driving it.

96blak54 · Jan 21, 2026

maillemaker said:
Yeah I now run 20W50. Putting in a bottle of STP Oil Treatment also works.

You're probably right. I don't drive it that hard anyway. Also I think you can hit 400 HP in a 302 with better cam, heads, and intake. Probably not necessary to go 347.

More cubes is more torque and not necessarily more hp when using the same heads and staying naturally aspirations. The torque is a ton of fun tho.

400hp is 100% do-able with a 302. 400 with the stock induction and a supercharger is 100% do-able too.

Daryl · Jan 22, 2026

I did exactly what you’re after: 302 to 347 and now realize that heads, cam and intake would’ve resulted in better drive ability, better mpg, far fewer headaches and hassles, and a fatter wallet without suffering very much at all in performance. 120k on the odd isn’t that much. A stock rebuild with or without a few hp mods, if you take care of your motor, will easily go an additional 150k.

If a supercharger is an option, start with your 302 block, unmolested, and find out the best combinations that will optimize a SC build.

96blak54 · Jan 22, 2026

If you really want to replace with a 347 stroker just for pure hobby, dont let us talk you out of it. Building cars is a great hobby and we all love it. Dont misunderstand us, we will be here cheering you on with your build and provide all the help we can. We just want to let you know the outcome is not as great as the anticipated expectations.

I swapped a 5.4l 2valve in my 96 and knowing now what I know I wished Id stayed with the 4.6l. Although its easy to revert back to the 4.6l, im to invested in this elephant of an engine 5.4l. There is a reason why Ford didnt install an engine this damn big in a Mustang. The thing sounds awesome, ran great, but its just to big and makes working on miserable. The torque output is fantastic for a NA engine but its un-usable in the car and creates poor performance. Now that Im older and more wise to vehicle performance, I understand this, but when I was younger I just had to build back bigger

Mustang5L5 · Jan 22, 2026

I agree. If you want to do it for the satisfaction of doing the project, i will absolutely state for the record I enjoyed every second of my build. It was, and still is fun.

I just have no desire to do it again

Musturd · Jan 22, 2026

Personally those blueprint 347’s are a lotta of bang for the money . You’ll probably make 350whp with one of those combos have awesome drivability etc . I gotta friend who just got one of their aftermarket block 347’s 8k for a long block hard to beat with 4 bolt mains . He’s been very happy with it has a d1x procharger on it . If the budget allows it I’d say go for it. Especially if it’s a street car on street tires the stock trans will last as traction won’t be the best .otherwise stock rebuild with good head gaskets studs and a vortech can make 400whp and drive like stock