302 to 347 Stroker: What You Need
Turning a 302 into a 347 is a stroke change: the stock 3.000 in stroke crank comes out and a 347 stroker kit goes in (crank, rods, pistons, rings and bearings, built around a 3.400 in stroke crank), and the block is bored .030 in over to 4.030 in. Boring alone only gets a 302 to about 306 ci. The 347 kits we list all use a 3.400 in stroke, a 4.030 in bore and 5.400 in rods.
Key takeaways
- A 347 is a stroked 302: 3.400 in stroke vs the stock 3.000 in.
- The kits we list use a 4.030 in bore, a .030 in overbore on a stock 4.000 in bore.
- A 347 stroker kit includes the crank, rods, pistons, rings and bearings; every 347 kit we list uses 5.400 in rods, and crank and piston material vary by kit.
- Plan for machine work, a clearance check and balancing.
- Not sure your block is a good candidate? Send us your combo.
Stock 302 vs 347 stroker
| Stock 302 | 302 bored .030 in | 347 stroker | |
|---|---|---|---|
| Bore | 4.000 in | 4.030 in | 4.030 in |
| Stroke | 3.000 in | 3.000 in | 3.400 in |
| Displacement | 301.6 ci | 306.1 ci | 347.0 ci |
| What changes | - | Bore only | Stroker kit (crank, rods, pistons, rings and bearings), plus the .030 in overbore |
The 347 kits we list
| Kit | Crank | Pistons | Rods |
|---|---|---|---|
| Eagle 14003030 | Forged | Forged | 5.400 in H-beam |
| Eagle 16003030 | Cast | Forged | 5.400 in I-beam |
| Scat 1-94160 | Cast | Hypereutectic (Keith Black) | 5.400 in I-beam |
| Scat 1-94165 | Cast | Forged (Icon) | 5.400 in I-beam |
Still deciding? Tell us your combo or call 310-784-1010.
What a 302 to 347 conversion needs
- A 289/302-family block that can be bored to 4.030 in. Have it checked before you buy parts.
- A 347 stroker kit: crank, rods, pistons, rings and bearings (3.400 in stroke crank, 5.400 in rods, pistons for a 4.030 in bore).
- Machine work: overbore and hone, plus a clearance check for the longer stroke, including rod-to-cam clearance.
- Balancing, where the kit listing doesn't say balanced.
- Gaskets, and the heads, cam and top end for your goal.
- Send us your combo and we'll go through it before you order.
Is a 347 stroker reliable?
How long any stroker lasts depends on the parts, the machine work and how it's used, so we don't make reliability promises. What you can control is the parts choice: each kit listing names its crank (cast or forged), pistons (forged or hypereutectic) and rods (I-beam or H-beam). Tell us your use and any power adder, and we'll help you match the kit.
Frequently asked questions
Is a 347 stroker reliable?
It depends on the parts, the machine work and how the engine is used, so we don't make reliability promises. Each kit listing names its crank (cast or forged), pistons (forged or hypereutectic) and rods (I-beam or H-beam); tell us your use and any power adder and we'll help you match the kit.
What is a 347 stroker engine?
A 347 is a 289/302 small block Ford with a 3.400 in stroke crank and a 4.030 in bore, which works out to about 347 ci. A 347 stroker kit includes the crank, rods, pistons, rings and bearings; the kits we list use 5.400 in rods.
Can you bore a 302 to a 347?
No. Boring a stock 302 from 4.000 in to 4.030 in only takes it to about 306 ci. Getting to 347 takes a stroker kit (crank, rods, pistons, rings and bearings) built around a 3.400 in stroke crank, so it's a stroke change, not a bore job.
What else do I need besides the kit?
A stroker kit includes the crank, rods, pistons, rings and bearings. Beyond the kit, plan for a 289/302-family block machined to a 4.030 in bore, a clearance check, balancing (where the listing doesn't say balanced), gaskets, and the heads, cam and top end for your goal. Send us your combo and we'll go through the list.
Ask a Coast High Ford builder
Ford strokers are what we build. Send your engine, goal and transmission, and a Coast High builder will get back to you. Or call 310-784-1010.
Shop this
- Eagle 347 stroker kit, forged crank, forged pistons (14003030)
- Eagle 347 stroker kit, cast crank, forged pistons (16003030)
- Scat 347 stroker kit, cast crank, hypereutectic pistons (1-94160)
- Scat 347 stroker kit, cast crank, forged pistons (1-94165)
- Small block Ford stroker kits
More guides
- 331 vs 347 stroker
- 347 stroker build cost: kit vs short block vs crate engine
- All Ford stroker and crate engine guides
Written by the Coast High Performance tech team. Checked by CHPTech Nov 4, 2026. Last updated November 4, 2026. Specs come from each manufacturer listing on our store. Questions? Call 310-784-1010.