The Stovebolt Site Forums The Shop Area The HiPo Shop Putting a 1970 v8 in a 59 truck

I am contemplating replacing my 261 with a 0.30 over 307 v8 engine. Aside from the obvious , ( motor mounts , gas pedal linkage, wiring for distributor exhaust manifolds (no Headers, I find them useless and a waste of money. etc.) , my biggest question would be will a GM Hei distributor fit without beating the firewall into submission? Front motor mounts ( factory style) or tubular style with side mounts. Any input would be help full . Thanks.

Hy Tommy, as your truck could have come with a V8 from the factory, and all the required parts to convert it are available either used or in the aftermarket, it should be a fairly easy swap once you have all the parts. However the H.E.I. distributor will not clear the factory firewall without modifying the firewall for clearance, one other point, some of the more performance V8s have large diameter harmonic balancers which would require modifications to the factory front mounts for clearance around that style of balancer, your 307 probably does not have that style of large balancer, hope that helps.

Hey 3B,
Thanks for the response. Yes I know a v8 was a factory option then, so all of the parts should be available. I was just wondering about the Hei dist., it is fool proof, you put it in and basically never fool with it again. I'm vertically challenged (short) so it's tough reaching anything under the hood, much less all the way in the back. I would guess the v8's had the rams horn exhaust manifolds? The 307 just has a small balancer,( it's really just a hub to mount the pulley on), so that shouldn't present a problem.
Thanks for the info'
Tommy

I've worked on a lot of worn out HEI's that the installer believed were "install it and forget it" items. The centrifugal advance weights and their pivot pins were worn beyond repair. Anything with any sort of mechanical component to it needs an occasional inspection and lubrication. A BB-sized dab of high temperature wheel bearing grease on the pivot pins would have prevented the wear, but those guys were too lazy to remove the distributor rotor about once a year. Ob the racing HEI's I built, I made bronze bushings for the pivot pins and opened up the holes in the weights to fit them for a much more predictable advance curve.
Jerry

When I acquired my 59' it had already been converted from a 235 to a 283. It used the original style V8 bell housing that mounted at 2 points to the rear engine crossmember. The front mount was a cradle that ran under the balancer and bolted to the front of the block( where a later V8 power steering pump would mount). The cradle mounted to the front crossmember with studs or rods that ran through the mount using rubber bushings similar to shock bushings. The 283 cleared the fire wall nicely.

I changed the design and made side mounts in order to free up the engine mounting points for a power steering pump. At the time I mocked up the engine the plan was to use an HEI, as such I moved the engine mounts forward 1" to aid in clearing the firewall. Since that time I have decided on using an MSD distributor and ignition box. I had planned to make brackets to move the bell housing mounts forward, I have since used a Muncie 4 speed (Car type) and tail shaft crossmember.

The center dump ram horn manifolds will clear everything on your truck.

Craig, Thanks for the response. I was wondering about the rams horn manifolds, that's good to know they will work.

Assuming the 307 physical dimensions are the same as a 283, you can use a small cap HEI. I did it on my 1957 truck when i had a 283 in it. It's a little close to the firewall, but works fine.
don

Don, They are pretty much the same engine, different stroke. I have seen people mention the small cap HEi, But I don't know that I have ever seen one. Is this a GM distributor ,or is it aftermarket. I know some later v8 had a smaller dist., but no vacume advance and I believe they were computer controlled. So that won't work. Thanks for the info.

It would probably be fairly simple to convert the point-type distributor that used the externally-adjustable points and the sliding window in the cap to use a GM HEI pickup coil and a reluctor instead of points, and mount the HEI trigger module on a remotely-mounted heat sink. That would solve the firewall clearance problem, eliminate periodic point changes, and make it possible to use one of the ultra high voltage "flamethrower" coils instead of the square-shaped HEI remote coils. The system would look almost original for the people obsessed with not using the big HEI distributor.
Jerry

Jeg's has a drop in HEI type distributor with vacuum advance, it's the same size as a point type distributor. The advantage to this electronic ignition, hotter spark easy set up, no fire wall clearance issues. There is no external ignition box required to run this, just drop it in and wire it up. You would still need to run a heavier external coil. https://www.jegs.com/p/JEGS/JEGS-SSR-Pro-Series-Distributors/1722417/10002/-1

That looks like a pretty good option for someone without the skill or machine shop facilities to build his own small-diameter electronic distributor. The cost is just short of highway robbery, however!
Jerry