1959 290 HP FI Heads

[Al R.]

Is there a known serial # or date when the 550 heads were no longer used on the 1959 290 HP FI engine?

[Bill M.]

Re: 1959 290 HP FI Heads

The Judging Guide has staggered bolt holes installed on '59 cars assembled as late as June or July.

[Al R.]

Re: 1959 290 HP FI Heads

Thanks Bill. Has anyone installed a set of the later double-hump heads on the 58-60 FI engines for a performance gain. If so, were any mods required to the FI units and what, if any noteworthy gains realized?

[Bill M.]

Re: 1959 290 HP FI Heads

Thanks Bill. Has anyone installed a set of the later double-hump heads on the 58-60 FI engines for a performance gain. If so, were any mods required to the FI units and what, if any noteworthy gains realized?

Chevy did that in production in 1961 and the gains were 25 (315-290) HP. The FI unit was upgraded during 1960, when the big valve aluminum heads were supposed to be released. I assume that the FI upgrade was required or Chevy wouldn't have spent the tooling money...

[Duke W.]

Re: 1959 290 HP FI Heads

In order to get maximum benefit from the "big port" heads, the FI manifold runners would have had to be enlarged to match the heads, but I've never been able to confirm by observation if this was done for the '61 big port FI engines.

Maximum benefit requires the heads to be "massaged" to improve the flow coefficient, and nearly all of the improvement will be above 4000 revs.

Torque/power will be improved across the rev range (but about equal peaks at the top end) by dropping in a 327 crank with "stroker rods", but some minor block clearancing will likely be required - not a big deal. With a .030" overbore you get about 311 CID.

With the longer stroke you can, get more top end without loss of much low end by replacing the Duntov cam with a LT-1 cam. Other than the head casting marks it will all look original with the same idle behavior as the original 283/290.

Duke

[Bill M.]

Re: 1959 290 HP FI Heads

In order to get maximum benefit from the "big port" heads, the FI manifold runners would have had to be enlarged to match the heads, but I've never been able to confirm by observation if this was done for the '61 big port FI engines.Duke

"59 bedplate to the right, '61 to the left. Gaskets are identical.