1956 265 GT stamped block

[Scott S.]

I am looking for information regarding the origin and destined use of the above noted motor. The motor is complete with 762 heads. Block casting date is I95.
Any help is appreciated.
Scott Sinclair

[Michael W.]

Re: 1956 265 GT stamped block

Any chance the block was cast in '65 and not '55? If so, the GT suffix might be a 195 HP 283 from a full size '66 model year car with pg transmission

[Scott S.]

Re: 1956 265 GT stamped block

Mike, The casting is 991 so it is a 1955 265 Cubic Inch motor.
Thank you,
Scott

[Dan A.]

Re: 1956 265 GT stamped block

Hi Scott

Colvin has it as a 1956 passenger car 265 240hp dual 4bbl, hi-lift cam usage.

[Dan A.]

Re: 1956 265 GT stamped block

The March 1957 Parts and Accessories Catalog has an Engine Serial Number and Suffix Chart. The GT suffix is not listed.

Of interest only two of the '56 Corvette suffixes are listed, FG and GR. The other three suffixes are not even listed under any of the other series identification numbers.

I could not find this chart in the April 1956 P&A. Although it may be there. The Chart for 1956 remains unchanged in the P&A through 1964. For '65 the P&A doesn't appear to give that information.

THe Canadian Finger Tip Facts lists the highest HP engine as 205hp. The very scant Corvette section repeats the passenger car specs. Thus it lists the 140hp 6 banger the 162 & 205hp passenger engines. Even lists the 162hp with a 2bbl. I have never heard of one in a '56 Corvette Before. No mention of the 210, 225 or 240hp engines. I don't have the U.S. version as I don't think there was a Corvette section in those.

[Dan A.]

Re: 1956 265 GT stamped block

Further minutia, the highest HP engine listed in the 1956 Dealer Showroom Album, is the 205hp engine. The 225 appears in the 1956 Chevrolet Corvette Engineering Achievements booklet though. The 210 and the 225 HP engines are listed in both the black and white and the color Showroom Brochures. No mention of the 240hp engine.

[Edward M.]

Re: 1956 265 GT stamped block

Scott;

Obviously a rare engine, and surprising that it was cast so early. Please keep us posted as you find out more about it.

[John S.]

Re: 1956 265 GT stamped block

Further minutia, the highest HP engine listed in the 1956 Dealer Showroom Album, is the 205hp engine. The 225 appears in the 1956 Chevrolet Corvette Engineering Achievements booklet though. The 210 and the 225 HP engines are listed in both the black and white and the color Showroom Brochures. No mention of the 240hp engine.

the 240hp is a dual quad settup with RPO449, a special high lift camshaft.

[Scott S.]

Re: 1956 265 GT stamped block

Gentlemen, The block is a 991 with 306 heads. The GT is a 240 HP version believed to be used in the Daytona speed weeks of 1956.
Scott

[Edward M.]

Re: 1956 265 GT stamped block

Gentlemen, The block is a 991 with 306 heads. The GT is a 240 HP version believed to be used in the Daytona speed weeks of 1956.
Scott

Scott;

I was thinking that GT engines were January, 1956 engines. A GT engine cast in Sept of 1955 is a surprise.

What is the sequence number on this engine? That would give us a rough idea of when it was assembled.

[Edward M.]

Re: 1956 265 GT stamped block

Gentlemen, The block is a 991 with 306 heads. The GT is a 240 HP version believed to be used in the Daytona speed weeks of 1956.
Scott

I thought you said it had 762 heads on it?

[Cecil L.]

Re: 1956 265 GT stamped block

From 56 Specs.

[John H.]

Re: 1956 265 GT stamped block

I am looking for information regarding the origin and destined use of the above noted motor. The motor is complete with 762 heads. Block casting date is I95.
Any help is appreciated.
Scott Sinclair

Scott -

Those "GT"-suffixed engines were built for use in NASCAR racing (passenger cars); they were essentially identical to the 2x4 240hp "GU" Corvette engine assembly, except they had no front engine mount bracket, no balancer spacer, used stamped sheet metal valve covers, and used the passenger car clutch disc, fork, and oil pan.

The complete Flint V-8 Bill Of Material for the "GT"-suffixed engine (compared with the "GU" and "SR" engines) is shown in Ken Kayser's "Countdown To Gold" article in the March, 2002 issue of "Vette Vues" magazine.

[John S.]

Re: 1956 265 GT stamped block

Scott -

Those "GT"-suffixed engines were built for use in NASCAR racing (passenger cars); they were essentially identical to the 2x4 240hp "GU" Corvette engine assembly, except they had no front engine mount bracket, no balancer spacer, used stamped sheet metal valve covers, and used the passenger car clutch disc, fork, and oil pan.

The complete Flint V-8 Bill Of Material for the "GT"-suffixed engine (compared with the "GU" and "SR" engines) is shown in Ken Kayser's "Countdown To Gold" article in the March, 2002 issue of "Vette Vues" magazine.

did the GT engines at daytona have the two or the three bolt exhaust manifolds? seeing that these cars were racing at daytona in january i would expect to see the earlier 306 heads. if that is the case a GT would have 306 heads and the later GU have the 762 heads.

[John H.]

Re: 1956 265 GT stamped block

did the GT engines at daytona have the two or the three bolt exhaust manifolds? seeing that these cars were racing at daytona in january i would expect to see the earlier 306 heads. if that is the case a GT would have 306 heads and the later GU have the 762 heads.

John -

The BoM shows the same 2-bolt 1st-design exhaust manifolds as the "GU" and "SR" engines, and 762 heads as-built at Flint V-8; who knows what they actually raced with. The BoM reflects the initial production release to Flint V-8; it may have had later changes.