347 Build - Looking for Parts Recommendations

[bulletpruf]

Fellas -

Building a mild 347 for my brother in law's 1968. This will be a weekend driver that will spend some time off-road. Has a C-4 and 3.50 gears. Will run 33 x 12.50 x 15 or similar size.

Needs to have good vacuum (power brakes), pump gas compression (9.5:1 or so), moderate build cost, good torque. Will run a carburetor, not FI. I'll assemble myself.

I wanted to go with a Blueprint 306 Bronco motor but the lead time is almost 4 months, and I need to have this finished and installed in about 3 months.

Since I have 3 different 302 cores (one in his truck, one on the engine stand, and the one in my '69) I might as well use one of these.

I'd prefer a new rotating assembly since I know once we magnaflux the crank, turn the crank, re-size the rods, add good rod bolts, etc., we're going to spend a fair hunk of change, and we're still using 50 year old parts.

For right around $1000, we can get a good 347 kit from Scat - this one looks about right - https://www.summitracing.com/parts/sca-1-94165/make/ford/year/1970

As for cylinder heads, the Blue Print heads with 60cc chambers sound good. They're about $1000 for the pair. https://www.summitracing.com/parts/mll-hp9009/make/ford

Figure I'll go with a basic dual plane intake, 600 cfm vacuum secondary carburetor with electric choke, electronic ignition, headers. I'll also need a balancer, new flexplate, rocker arms, and a mild hydraulic roller cam & lifters.

I'll get the local machine shop to balance, bore the block, deck to zero deck height, install cam bearings, and I can handle the rest.

This should be 350+ hp and 350+ ft/lbs of torque. More than he needs, but that's fine.

Anyone have any thoughts/recommendations?

Thanks,

Scott

 

[AZ73]

I have a 347 built with Scat crank and rods. Twisted flow heads. To get my Torque down low (which you'll need with 3.50 gears) I had this cam ground. It's a Jay Allen design (Before he disappeared) for Torque between about 1200 and 6000 rpm (vs the high revving SBF cams for mustangs). It's very similar to another popular Comp cam for 347's which number escaped me at the moment. Plenty of vacuum. Or just call comp and tell them what you're doing. They'll recommend their off the shelf version.

 

[bulletpruf]

I have a 347 built with Scat crank and rods. Twisted flow heads. To get my Torque down low (which you'll need with 3.50 gears) I had this cam ground. It's a Jay Allen design (Before he disappeared) for Torque between about 1200 and 6000 rpm (vs the high revving SBF cams for mustangs). It's very similar to another popular Comp cam for 347's which number escaped me at the moment. Plenty of vacuum. Or just call comp and tell them what you're doing. They'll recommend their off the shelf version.

Thanks for the details. I like Comp Cams products, so I'll check with them.

Are you running a carb or EFI? If carb, what intake and carb did you use?

Scott

 

[AZ73]

Original carb (Holley Truck Avenger), now sniper EFI. My engine builder put on an RPM air gap which I really didn't want because it adds height, but he insisted it would perform better on lower RPM motors. I read comparisons since then where the difference in negligible, but with the 1" BL and drop down air filter, it fits fine. If you're tight for space, go with the RPM

You can read all the specs here:

https://classicbroncos.com/forums/showpost.php?p=2350889&postcount=90

 

[Speedrdr]

On the 347 stroker I had built, I went with an edlebrock performer intake (off idle power) edlebrock 1406 electric choke carb, AFR heads. Roller rockers and roller cam(don’t have the spec sheet handy). Supposed to be about 450 HP. not sure if that helps or not.

Randy

 

[bbaltered]

It all looks good but, if you zero deck the block with flat tops you're going to be well over 9.5.

 

[c17jack]

Fellas -

Building a mild 347 for my brother in law's 1968. This will be a weekend driver that will spend some time off-road. Has a C-4 and 3.50 gears. Will run 33 x 12.50 x 15 or similar size.

Needs to have good vacuum (power brakes), pump gas compression (9.5:1 or so), moderate build cost, good torque. Will run a carburetor, not FI. I'll assemble myself.

I wanted to go with a Blueprint 306 Bronco motor but the lead time is almost 4 months, and I need to have this finished and installed in about 3 months.

Since I have 3 different 302 cores (one in his truck, one on the engine stand, and the one in my '69) I might as well use one of these.

I'd prefer a new rotating assembly since I know once we magnaflux the crank, turn the crank, re-size the rods, add good rod bolts, etc., we're going to spend a fair hunk of change, and we're still using 50 year old parts.

For right around $1000, we can get a good 347 kit from Scat - this one looks about right - https://www.summitracing.com/parts/sca-1-94165/make/ford/year/1970

As for cylinder heads, the Blue Print heads with 60cc chambers sound good. They're about $1000 for the pair. https://www.summitracing.com/parts/mll-hp9009/make/ford

Figure I'll go with a basic dual plane intake, 600 cfm vacuum secondary carburetor with electric choke, electronic ignition, headers. I'll also need a balancer, new flexplate, rocker arms, and a mild hydraulic roller cam & lifters.

I'll get the local machine shop to balance, bore the block, deck to zero deck height, install cam bearings, and I can handle the rest.

This should be 350+ hp and 350+ ft/lbs of torque. More than he needs, but that's fine.

Anyone have any thoughts/recommendations?

Thanks,

Scott

I'm running a 347 Stroker with a Comp Cam 281HR which is a hydraulic roller cam with retro fit link bar lifters. It has a decent idle nothing crazy erratic and i have plenty of vacuum for my brakes. Builds plenty of torque down low and is a really fun package. Only difference is i'm running Holley Sniper.

https://www.compcams.com/magnum-220-220-hydraulic-roller-cam-k-kit-for-ford-5-0l.html

 

[bulletpruf]

Original carb (Holley Truck Avenger), now sniper EFI. My engine builder put on an RPM air gap which I really didn't want because it adds height, but he insisted it would perform better on lower RPM motors. I read comparisons since then where the difference in negligible, but with the 1" BL and drop down air filter, it fits fine. If you're tight for space, go with the RPM

You can read all the specs here:

https://classicbroncos.com/forums/showpost.php?p=2350889&postcount=90

Thanks, I'll check it out.

On the 347 stroker I had built, I went with an edlebrock performer intake (off idle power) edlebrock 1406 electric choke carb, AFR heads. Roller rockers and roller cam(don’t have the spec sheet handy). Supposed to be about 450 HP. not sure if that helps or not.

Randy

Thanks for the input.

It all looks good but, if you zero deck the block with flat tops you're going to be well over 9.5.

I'll do the math on compression ratio. I can always run heads with larger chambers if needed, or get pistons with a dish.

I'm running a 347 Stroker with a Comp Cam 281HR which is a hydraulic roller cam with retro fit link bar lifters. It has a decent idle nothing crazy erratic and i have plenty of vacuum for my brakes. Builds plenty of torque down low and is a really fun package. Only difference is i'm running Holley Sniper.

https://www.compcams.com/magnum-220-220-hydraulic-roller-cam-k-kit-for-ford-5-0l.html

Thanks. I'll check out the specs.

 

[theshadow]

You may want to have the machine shop notch the cylinders for the rod bolts before final hone vs you doing it after the fact and risk the collateral damage.

I had originally planned on doing the notching for mine and then forgot to tell the shop until after the hone and they had to go back in after.

Sent from my Pixel 3 using Tapatalk

 

[bulletpruf]

You may want to have the machine shop notch the cylinders for the rod bolts before final hone vs you doing it after the fact and risk the collateral damage.

I had originally planned on doing the notching for mine and then forgot to tell the shop until after the hone and they had to go back in after.

Sent from my Pixel 3 using Tapatalk

Good point. Thanks