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Alex V. · 09-11-2016, 01:40 PM

My understanding is that the L30 RPO in passenger cars was rated at 275HP - 1.94" valve, 64CC double hump heads with 10- or 10.25:1 compression, 300HP cam, and a Quadrajet. The '67-8 Corvette base 327 was essentially the same engine with only a different carburetor (Holley?) advertised as 300HP. Is it possible the 240HP truck 327 was only a 220HP with the Quadrajet upgrade? '68 Brochure lists it as 240 horse, 330 torque (up 10 from the '67 220 horse) and 8.5:1 compression, so by conjecture it seems logical the innards are closer to an up-rated 220 HP than a de-rated 275 HP.

Also, the 480 heads (which I have a set of along with a date-matched '67 "YS" suffix 220HP block) list as 70CC chambers.

09-11-2016, 01:40 PM	#6
Alex V. Registered User Join Date: Mar 2013 Location: Campbellsville, KY Posts: 888	Re: 327 info needed My understanding is that the L30 RPO in passenger cars was rated at 275HP - 1.94" valve, 64CC double hump heads with 10- or 10.25:1 compression, 300HP cam, and a Quadrajet. The '67-8 Corvette base 327 was essentially the same engine with only a different carburetor (Holley?) advertised as 300HP. Is it possible the 240HP truck 327 was only a 220HP with the Quadrajet upgrade? '68 Brochure lists it as 240 horse, 330 torque (up 10 from the '67 220 horse) and 8.5:1 compression, so by conjecture it seems logical the innards are closer to an up-rated 220 HP than a de-rated 275 HP. Also, the 480 heads (which I have a set of along with a date-matched '67 "YS" suffix 220HP block) list as 70CC chambers. __________________ Alex V. ------ 1967 C10 Suburban, 350/NP435, Green/Green, PS, PB, HD cooling, charging, shocks, and springs. 1985 GMC C3500 SRW, Sierra Classic, 454/TH400, white/blue. Last edited by Alex V.; 09-11-2016 at 01:51 PM.